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Section 11 : Occupational Health223 Introduction & General Concepts L S. Vaz, A K Jindal, Puja Dudeja 1270

224 Health Problems in Important Occupations Ashok K. Jindal, Puja Dudeja 1271

225 Organ / System Diseases Peculiar to Occupational SettingsLeo S Vaz, Ashok K. Jindal, Puja Dudeja

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226 Industrial AccidentsAshok K. Jindal, Leo S. Vaz, Puja Dudeja

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227 Industrial Toxicology Ashok K. Jindal, Puja Dudeja 1281

228 General Measures of Prevention & Control of Occupational Diseases Ashok K. Jindal, Puja Dudeja 1286

229 Ergonomics Leo S Vaz 1288

230 Physical Working Environment Leo S Vaz, Ashok K. Jindal 1290

231 Social Security and Labour Laws Ashok K. Jindal, Puja Dudeja 1295

232 Medical Evaluation of Workers Leo S Vaz 1298

233National Programme for Control and Treatment of Occupational Diseases

Leo S Vaz, Ashok K. Jindal, Puja Dudeja

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223 Introduction & General Concepts

Leo S. Vaz, Ashok K. Jindal, Puja Dudeja

Definition‘Occupational health should aim at the promotion and maintenance of the highest degree of physical, mental and social well being of workers in all occupations; the prevention amongst workers of departures from health caused by their working conditions; the protection of workers in their employment from risks resulting from factors adverse to health; placing and maintenance of the worker in an occupational environment adapted to his physiological and psychological equipment and to summarize : the adaptation of work to man and of each man to his job’.

- Joint Committee of WHO and ILO, 1950

Health Hazards in Industry Hazards in the industry can be due to physical, chemical, biological, mechanical and psychosocial causes. Table - 1 gives

the physical hazards and their adverse health effects due to them.

Chemical Hazards : Almost all the occupations in industry have scope of exposure to some chemical substance or the other. These substances may be solids, liquids or gases, vapours, fumes, dusts, smoke, mist, fog or smogs.

Biological Hazards : Viruses, rickettsiae, bacteria, fungi, protozoa and helminthes may be transmitted in certain occupations.

Mechanical Hazards : Mechanical factors of importance in illness and injury in industry are defective design of machinery, defective procedures, unguarded machinery, protruding and moving parts, falling heavy objects and poor ergonomics.

Psychosocial Hazards : Factors responsible for psychosocial illness are frustration due to type of work, risks involved in work, monotony, long working hours, lack of recognition, lack of job satisfaction, poor remuneration, poor man management, lack of welfare activities and tensions at home and place of work. The indicators for psychosocial group of are chronic absenteeism, mass leave lock outs, strikes and unexplained reduction in production.

Table - 1 : Physical Hazards in an industry

Hazard Occupation Health Effects

HeatFoundry, glass, heavy metal industries, underground mines, vulcanization of rubber, spinning room of textile industry

Heat stroke, heat hyperpyrexia, heat exhaustion, heat syncope, heat cramps

ColdArmed forces, food processing and preservation industry

Chill blains, frost bite, trench foot, erythrocyanosis

Light Mines, driving Eye strain, eye fatigue, nystagmus, headache

Noise Machinery in factories producing loud noiseAuditory : Auditory fatigue, permanent hearing loss; Non auditory : Nervousness, fatigue, decreased efficacy, annoyance, raised blood pressure, loss of sleep

Vibration Pneumatic drill usersVibration induced white fingers due to Raynaud’s phenomenon, osteoarthritis of wrists, elbows, shoulders.

UV radiation Arc welding Glare and dazzle, pain and gritty feeling in the eyes

Ionizing radiation

Radiography, radioisotope use, processing of plastics, food preservation, industrial radiography, industrial hydrology, chemical industry and medical research

Cancer, leukemia, aplastic anemia, pancytopenia

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224 Health Problems in Important Occupations

Ashok K. Jindal & Puja Dudeja

Health Hazards in Foundry WorkFounding consists of pouring molten metal into a mould which is made to the outside shape of a pattern of the article required and contains, in some case a core which will determine the dimensions of any internal cavity. The basic principles of foundry work have hardly changed over the years though a lot of modernization has come, making plants more mechanized and automatic. Molten metal is introduced into the mould. After cooling occurs, the mould is subjected to a ‘shakeout’ procedure, which releases the casting and removes the core. The casting is then cleaned and any extraneous metal is removed from it.

ProcessThe various processes involved in foundries include Moulding & pattern making, Core making, Melting & pouring, Shakeout (Knockout) and Dressing & cleaning.

The various process outlined in the preceding section give rise to heat, molten metal splashes, dusts, noise, gases and vapours in the foundry environment. If these hazards are not controlled or contained, serious health effects in exposed workers can result. Foundry work also involves various manual operations which carry a risk of physical injury. The occupational health and safety issues are encountered during foundry activities include Physical hazards, Radiation hazards, Respiratory hazards, Electrical hazards, Noise exposure, Burial hazards, and Fire & explosions. The common and important ones are as follows :

Silicosis : Silica dust presents a prominent hazard of silicosis. This dust is generated during mixing, moulding, shakeout and dressing operations, and during sand conditioning for re - use. The dust arises from quartz in the sand, and the concentration of free silica in the air varies with the handling process, the efficiency of dust control, the chemical composition of the sand and the physical state of the sand, that is, whether the sand is screened or un-screened, wet or dry and is either dumped or re-milled, with water and binder added before it is re - used. The amount of respirable dust is increased by such re - use. Sand is dry at the mixing or ‘mulling stage prior to mould making’, and at the shakeout stage; this dry sand is potentially more hazardous than wet sand. Screened sand does not produce as much silica dust as unscreened sand and pure quartz sand is more hazardous than olivine sand. Abrasive blasting processes may involve the use of sand containing high concentrations of free silica.

Irritation, Allergy, Asthma, Metal Fume Fever, Malignancy: In addition to dusts, the air in foundries may contain the potential irritants like formaldehyde, various amines and phenol. These contaminants are generated primarily by the core making and moulding processes, and may irritate the eyes and the respiratory tract. Some hardwoods used in

pattern making can release products which may cause asthma in exposed workers. Vapours from various resins can initiate severe allergic reactions. Carbon monoxide gas is produced in substantial amounts by a variety of furnaces. Exposure to concentrations of 500 to 1000 ppm for approximately 30 minutes may precipitate headache, accelerated breathing, nausea, dizziness and mental confusion. Thus a possible secondary effect of exposure is an increased risk of accident and injury to the worker. Various metal fumes may be generated during founding processes, especially during melting and pouring operations. Lead, magnesium, zinc, copper, aluminum, cadmium, antimony, tin and beryllium fumes are commonly present in non - ferrous foundries. Iron oxide is the major fume generated in iron and steel operations. ‘Metal fume fever’ may result from exposure to these contaminants. This is an acute illness of short duration which commences some hours after inhalation of the metallic fumes. The initial symptoms are flu - like; nausea, headache, dry throat and coughing, and muscular pains, chills and sweating may occur later. Recovery is usual within 24 hours after removal from exposure. The lead hazard in furnace cleaning, dross disposal and the fettling of lead alloys deserves particular attention. Besides dusts & fumes in foundries are known to have carcinogenic properties.

Occupational Dermatitis : Formaldehyde, isocyanates, various resin products associated with pattern making and core making processes can irritate the skin and may precipitate allergic skin reactions.

Noise Induced Hearing Loss and Related Effects : The foundry process generates noise from various sources, including scrap handling, furnace charging and EAF melting, fuel burners, shakeout and mould / core shooting, and transportation and ventilation systems. Some fettling workers have been shown to be exposed to levels of noise over 100 db; shakeout and knockout processes are typically associated with readings of 90 - 110 db. Mechanical sand mixing processes and forced draught furnaces may produce noise levels of 90 - 100 db. Extraction fans, die - casting machines, core - making and shell - making equipment may also be sources of excessive noise.

Vibration : Pneumatic grinding and chipping tools used in dressing the cooled castings may cause vibration induced health effects in operators. Hazardous vibration equipment may also be utilized in shakeout and core removal operations.

Heat and Heat Stress : Radiant heat is the major contributor to the heat load imposed on the worker by the environment. Convective heat transfer adds to this radiant heat. Protective clothing is worn for protection against the heat radiating from the heat sources and against contact with molten metals. Such clothing greatly restricts the potential for body heat loss via evaporation. The effects of heat range from decreased concentration to painful cramps, fainting, heat exhaustion and heatstroke. Heat stress can also aggravate the effects of exposure to other agents such as noise and carbon monoxide.

Accidents & Injuries : Serious burns may result from splashes of molten metal in the melting land pouring areas of foundries. Frequent, unprotected viewing of white - hot metals in furnaces and pouring areas may cause eye cataracts. Eye injures from molten metal or fragments of metal may occur in pouring and

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dressing areas, during continuous casting processes, non - ferrous molten metals, such as copper and aluminum, may explode violently if they contact water. Injuries related to the manual handling of materials, and injuries due to falls, may occur. Grinding wheels used for dressing small articles may result in hand injuries.

Preventive MeasuresMonitoring & Evaluation of Exposure : Monitoring of the work environment, personal monitoring and biological monitoring should be undertaken, In some cases, biological monitoring may be required to supplement static or personal monitoring. When developing a monitoring programme in foundries, due consideration should be given to the hazards in the foundry. In the control of health hazards due to specific contaminant, where it has been demonstrated that the exposure of the employee to the contaminant is approaching the relevant exposure standard, or where biological monitoring indicates that an unacceptable exposure is occurring, immediate action must be taken to reduce the health hazard and intensive monitoring should continue. Worker exposure to dusts, gases and vapours should be kept as low as workable. Exposures should be well below the exposure standards recommended in the Factories Act 1948.Engineering Control Measures(a) Elimination/substitution and process modification viz.

quartz sand can be substituted by olivine sand in ‘sand blasting’ as it is less hazardous. Silica - based polishing pastes should not be used in metal cleaning operations.

(b) Engineering controls like local exhaust ventilation should be provided at the mixing or mulling stage as the sand is dry. It is a means of controlling carbon monoxide emissions at their source. Total enclosure of abrasive and cleaning operations should be provided. Potentially irritant vapours or fumes generated in core making or moulding processes should be collected by exhaust ventilation at the point of emission.

(c) The reduction of noise at the source or in the transmission path should be achieved wherever workable.

Preventing Physical Injures(a) Mechanically propelled vehicles or machinery should

be inspected regularly. Contact between molten metal and water must be avoided. All ladles and other equipment used for handling metal should be completely dry before contacting molten metal.

(b) Good house keeping practices are to be followed.(c) Floors around furnaces should be of slip - resistant, non -

combustible material, kept free of obstructions and cleaned regularly.

(d) Persons would be prohibited from entering furnace areas when the temperature exceeds 50°C.

(e) Foundries should be equipped with safety blankets, automatic emergency showers or hoses to extinguish burning clothing.

(f) Self - contained breathing apparatus must be used in emergencies when high carbon monoxide concentrations are suspected.

Minimizing the Risk of Heat Illness : People who have any history of heat intolerance or a circulatory disorder, anyone

recovering from a fever, and any dehydrated worker must be regarded as being in a high - risk category for heat illness. Unacclimatised persons must be given time to acclimatize to work in the heat. Planned job rotation can assist in reducing exposure to heat. Cool water should always be available in close proximity to hot working areas and encouragement be given for the use of these facilities. The exposure of workers to radiant heat can be reduced by the strategic positioning of shields between workstations and heat sources. Clothing should be carefully selected so that a balance between protection and facilitation of heat loss through evaporation is achieved.

Personal Protective Equipment : Personal protective equipment such as goggles, padded gloves, ear muffs must be used by the workers. If the mechanical ventilation in the foundry is not adequate in removing the dust at all points of contamination, the wearing of personal respiratory protective equipment, such as a face mask/respirator, is a complementary preventive measure together with local exhaust ventilation. If operators are required to work inside the enclosure, a continuous - flow, air - line respirator must be worn.

Education and Training : All employees working with foundry hazards must be informed of the hazards and the precautions necessary to prevent damage to their health. Employees exposed to contamination hazards should be educated in the need for, and proper use of, facilities, clothing and equipment and thereby maintain a high standard of personal cleanliness.

Health Assessment : Pre - placement examination and periodic medical examination of all worker should be done annually for early identification of health effects and for documentation for compensation claims.

Noise Management Techniques :Enclose the process buildings and / or insulate them ●Cover and enclose scrap storage and handling areas, as ●well as shake out and fettling processesEnclose fans, insulate ventilation pipes and use dampers ●Implement management controls, including limitation of ●scrap handling and transport during night time. Noise abatement measures should achieve the ambient noise levels

Health Problems of Agricultural WorkersAgriculture is art/practice of cultivating land. WHO defines it as an industry comprising of all forms of activities connected with growing, harvesting and primary processing of all types of crops. It also includes activities related to breeding, raising caring for animals in the farms and tending gardens and nurseries. Any person engaged either temporarily/ permanent in activities related to agriculture is called as agricultural labour. Agricultural sector occupies a key position in our country. It provides employment to about 65 per cent of the working population of India (5). It is the major source of income for about three - fourths of India’s populations who live in villages. Agricultural workers constitute by far the largest segment in the unorganized sector. Most of them are listed as cultivators (large, medium and small) of whom approximately 50% belong to the category of small and marginal farmers. A significant number of them are engaged in livestock, forestry, fishing, orchards and allied activities. Agricultural workers constitute

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the most neglected class in Indian rural structure. Their income is low and irregular. They do not possess any skill or training and have no alternative employment opportunities. Socially, a large number of agricultural workers belong to scheduled castes and scheduled tribes. Therefore, they are a suppressed class. They are not organized and they cannot fight for their rights (6). Occupational hazards of agriculture sector are given in Table - 1 (7).

The various types of respiratory diseases in agriculture are highlighted in Table - 2.

Table - 2 : Respiratory diseases in agriculture

Agent Disease

Saw dust Carcinoma nasal septum

Sugar cane dust Bagassosis

Cotton, flax, sisal or hemp Byssinosis

Husk with thermophilic actinomycis (Micropolyspora faeni)

Farmer’s lung

Tobacco dust Tobaccosis

Dusts of grains, rice, coconut fibres, tea

Asthama, COPD

Cocoa bean handling Respiratory allergy

Others : Agriculture being labour intensive activity musculo - skeletal disorders are the leading cause of the occupational ill health (8). This risk of musculo - skeletal disorders is higher in agricultural workers because of the longer working hours, practice of lifting heavy weights and inconvenient work posture. There is poor application of ergonomics principle to agricultural tools. There are no legislations related to health, safety and welfare of agricultural workers. There is no social security for agricultural workers other than crop insurance. There is no act to provide welfare to the workers. Living condition of these people, low educational status, lack of medical facilities in rural areas aggravate there problems. Being in close proximity to animals agricultural labour also faces hazards of zoonosis.

Women in AgricultureWomen in India are the major work force in agriculture and perform almost all the agricultural activities. Since agriculture by its nature is an unorganized sector and in case of women, their contribution is generally unrecognized. In fact some economist have use the term ‘Labour for Love’ while describing the status of Indian women who is married with farmer’. A significant proportion of women work force in rural areas is dependent for their livelihood (8). The lives of these women are plagued by high levels of occupational, poverty - induced diseases and reproductive health problems. Abortions, premature delivery, and still birth are outcomes of their deprived socio - economic,

Table - 1 : Occupational Health Hazards of Agriculture

Exposure Health Effect Remarks

Weather, Climate Dehydration, heat cramps, heat exhaustion, heat stroke, skin cancer

Most agriculture occupations are performed outdoors

Snakes, insects Fatal or injurious bites and stings Close proximity in high incidence

Sharp tools, farm equipment

Injuries ranging from cuts to fatalities, hearing impairment from loud machinery

Most farm operations require variety of skills for which workers have little formal training and there are few hazard controls on tool equipment

Physical labour carrying loads

Numerous types of (largely unreported) musculoskeletal disorders, particularly soft - tissue disorders, e.g. back pain

Agricultural work involves awkward and uncomfortable conditions and sustained carrying of excessive loads

PesticidesAcute poisonings, chronic effects such as neurotoxicity, reproductive effects and cancer

More hazardous products are used in developing countries with minimal Personal Protective Equipment (PPE)

Dusts, fumes, gases, particulates

Irritation of the eyes and respiratory tract, allergic reactions, respiratory diseases such as Byssinosis, bagassosis, asthma, chronic obstructive pulmonary disease and hypersensitivity pneumonitis

Agricultural workers are exposed to a wide range of dusts and gases from decomposition of organic materials in environments with few exposure controls and limited use of PPE use in hot climates.

Biological agents and vectors of disease

Skin diseases such as fungal infections, allergic reactions and dermatoses

Workers are in direct contact with environmental pathogens, fungi, infected animals and allergenic plants

Parasitic diseases such as schistosomiasis, malaria, sleeping sickness, leishmaniasis, ascariasis and hookworm

Workers are in direct contact with environmental pathogens, fungi, infected animals and allergenic plants

Animal - related diseases or zoonoses such as anthrax, bovine tuberculosis and rabies (at least 40 of the 250 zoonoses are occupational diseases in agriculture)

Workers have ongoing, close contact with animals through raising, sheltering, and slaughtering exposed to a mix of biological agents, pesticides, and diesel fumes, all linked with cancer

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cultural, and political conditions and gender inequities (9). The socio - cultural norms and practices that endanger the women’s health are reflected in their low age at marriage and low age at first childbirth. Women working in fields shoulder the double burden of work - within home and outside home - and stretch themselves beyond their physical capabilities to procure adequate economic security for their families. They bear the brunt of the deprivation due to the gender inequities. The low nourishment and the resultant general under - nourishment lead to illnesses, which prevent them from translating their labour endowments into economic resources. In short, the poverty of the women agricultural workers encompasses a wide rage of unmet needs and gender - specific inequities including lack of adequate access to education, employment, resources as well a range of violence, relative powerlessness, and feelings of hurt, low self - esteem and denial of identity.

LegislationsThough agriculture is the major occupation in India and gives not only employment but is also responsible for providing food security to the nation but unfortunately only lip service has been paid in providing social security for the welfare of the workers engaged in this class. As a result they can go into penury due to floods, droughts, extensive loans under taken

from money lenders to buy costly fertilizers and pesticides. The general public health system of the country is also in a poor state and has very little to offer as preventive, promotive and curative care to this class. This is evident from the large number of suicides that have taken place among farmers. There is a definite need to take case for social security for this sector. In this connection government has come out with National Policy for Farmers 2007(10). The objective of the policy is to improve the economic viability of farming through substantially improving net income of farmers. The policy emphasis on increased productivity, profitability, institutional support, and improvement of land, water and support services apart from provisions of appropriate price policy, risk mitigation measures and so on. Government of India has recently taken several initiatives such as the National Horticulture Mission, the National Bamboo Mission, reforms in agricultural marketing, the revitalization of cooperative credit structure and setting up of the National Fisheries Development Board and the National Rainfed Area Authority. More recently, the National Food Security Mission and the Rashtriya Krishi Vikas Yojana (Additional Central Assistance Scheme) have been approved to substantially enhance investment in agriculture and increase production and productivity.

225 Organ / System Diseases Peculiar to Occupational Settings

Leo S Vaz, Ashok K. Jindal & Puja Dudeja

Occupational Lung DiseaseAn occupational lung disease is a lung condition that develops as a result of a person inhaling harmful substances at his or her place of work. Occupational lung diseases are the most common work - related illness but fortunately many are preventable or controllable with proper treatment. Occupational lung diseases are classified into two major groups : pneumoconiosis, caused by dust that gets into the lungs, and hypersensitivity diseases, such as asthma, that are caused by the lungs’ overreaction to airborne pollutants. Table - 1 depicts important features of various lung diseases.

PneumoconiosisBy ILO definition it is the accumulation of dust in the lung and tissue reaction to its presence. The concept of using the term pneumoconiosis has undergone a change. Earlier this term was used to describe all lung related problems caused by any kind of dust (17). However the term should be used

for all dust damage to the alveolar part of lung including the airways which do not have mucociliary lining (18). Therefore the term does not include bronchitis, asthma or cancers. In other words the inorganic dusts like silica, asbestos and coal cause pneumoconiosis where as organic dust like cotton and cane sugar cause bronchitic changes and do not qualify to be called pneumoconiosis.

Body Defence Mechanism : Dust is an aerosol consisting of finely divided particulate matter, size 1μ- 150μ, organic or inorganic, generally inanimate and produced by attrition of solid matter by processes such as cutting, sawing, crushing, grinding, blasting etc. Dust particles 10μ or more in size are released in size settle down on the floor due to effect of gravity. The dust particles of such larger size which are inhaled are mostly arrested by the upper airway filter of hairs in the nostrils and by the folds of mucosa over the turbinates and carried down in the mucus and swallowed over airway filter, carried in the mucus back to the larynx and swallowed. Irritant particles are thrown out by reflex acts of coughing and sneezing. Of smaller particles those are inhaled in size of 3 - 10μ are tackled by the mucociliary lining of lower airway, filter, carried in the mucus back to the larynx and are swallowed. Particles 0.5μ - 3μ in size reaches the alveoli and get deposited causing damage to the lungs, producing various types of pneumoconiosis. Particles less than 0.5μ in size have a slim chance of settling down in

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the lungs and are mostly breathed out in the expiratory air.

Silicosis : Silicosis is a disease caused by breathing air containing silica in its free state, as quartz (SiO2). The pathological result is a generalized fibrotic change and development of miliary nodules of variable sizes in both lungs. The clinical manifestations are shortness of breath, decreased chest expansion, a lessened capacity for work and chronic bronchitis with the absence of fever and characteristic X - ray findings. There is an increased susceptibility to tuberculosis. The diagnosis of the disease mainly depends upon occupational history symptom complex and the radiological findings. The pathological process starts only when the dust particles, which contain silica in a free state such as quartz (SiO2), reach the alveoli. Most of the dust inhaled is expelled by the ciliated epithelium and some part is eliminated by phagocytosis, which brings up the particles and discharges them to the ciliated epithelium and the cough mechanism expels them. However, when the fine particles are present in the atmosphere in a large quantity, some find way to the finer air passages. They first cause the inflammation of the ciliated epithelial cells with their subsequent destruction, reducing the first line of defense. Epithelial cells crowded with silica dust get aggregated into definite clumps around which fibrosis occurs. This damage produced in the lung is permanent. It is liable to activate the preexisting tubercular focus and develop tuberculosis. The disease finally produces emphysema and corpulmonale.

Very little can be done once the disease has set in and therefore, prevention is most important, pre - placement & periodic health examinations of the worker are important. Chest X Ray is to

be taken to see if the individual has pulmonary tuberculosis or any other lung disease. Basic lung function tests should be carried out, including measurement of the Vital Capacity & Forced Expiratory Volume in one second. Dust control is the most important engineering procedure to reduce risk. If a significant number of workers develop silicosis within 20 - 25 years of first employment, the dust control measures should be suitably revised.

Asbestosis : Asbestos is a fibrous material. These are silicates; silica combined with bases like magnesium, iron, calcium, sodium and aluminum. These are of two types - serpentine and amphibole. However, 90% of production is of serpentine variety. Asbestos used in the manufacture of asbestos cement, fireproof textiles, roof tiling, brake lining, gaskets, and such other items. Asbestos fibres are inhaled and fine dust gets deposited in the alveoli. These are insoluble and cause chronic irritation resulting in pulmonary fibrosis of lungs. It can also cause carcinoma of bronchus and mesothelioma of pleura and peritoneum (more due to amphibole variety). These possibilities are more when exposure is coupled with smoking. The disease appears after an exposure of 5 to 10 years. The fibrosis is peribronchial, diffuse and more near the bases in contrast to fibrosis due to silicosis. Clinically, patient gets cough, pain in chest and dyspnoea disproportionate to the clinical signs in lungs. In advanced cases, there may be clubbing of fingers, cardiac failure and cyanosis. Sputum show asbestos fibres coated with fibrin called “asbestos bodies”. X - ray chest shows a ground glass appearance in lower parts of lungs. Disease is progressive even after removal from exposure. Preventive

Table - 1 : Comparison of Different Types of Lung Diseases

Silicosis Anthracosis Asbestosis Byssinosis BagassosisFarmers’

lungSiderosis

Type Major Major Major Major Major Major Major

Occupational exposure

Silica dust mines, tunnels : quarries, foundries; potteries and soap

Coal miners and handlers : carbon electrode manufacturing

Asbestos industry; brake and fire resistant product manufacturing

Exposure to cotton dust released during cording, spinning and weaving

Fibrous residue of sugar cane in cardboard and paper industry

Agricultural workers

Foundry workers, grinders and welders

Initiating stimulus

Chemical Unknown Mechanical Allergy Infection Infection Absent

Pathogenesis Fibrosis initiated by silicic acid leading to nodular fibrosis, emphysema and right heart failure. Pulmonary TB in 50% cases

Two distinct stages - simple CWP and PMF. Average time taken is 12 years

Asbestos fibres initiate fibrosis of pulmonary tissue, emphysema and its associated complication

Cotton dust inhalation produces allergic reaction leading to broncho - spasm, emphysema and its complications

Fungal infection leading to acute bronchitis and broncho - pneumonia

Fungal infection leading to bronchitis and broncho - pneumonia

No tissue reaction or functional impairment though lungs are loaded with iron dust.

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measures include :(a) Adopt all measures for dust control. The legal exposure

limit in India is 23 fibres/ml of air. Fig.-1 shows various methods of dust control.

(b) Substitute it with safer materials like glass fibres, calcium silicate, plastic foam etc. where feasible.

(c) Use safer varieties of asbestos (chysotile and amosite).(d) Periodic medical examination of workers and elimination

of susceptible from workforce.(e) Use of personal protective measures.(f) Good housekeeping & the use of vacuum cleaners.(g) Use of respirators & protective clothing is to be

encouraged.(h) Health education of the workers.(j) Continuing research to find out safer substitutes (19-24).Anthracosis or Coal Worker’s Pneumoconiosis : (Synonyms: Anthracosis, Coalminer’s consumption, phthisis melanotica, black spit). The diseases due to inhalation of dust in coal mines are simple coal - worker’s pneumoconiosis (CWP) and complicated coal - worker’s pneumoconiosis. Simple CWP is due to chronic exposure to coal dust with a low level of other mineral dust contamination. In this condition, the progression of small rounded opacities may be associated with only a slight loss of ventilation, which is insufficient to produce any disability. It can be very difficult to differentiate these effects from those of aging and cigarette smoking. Complicated CWP is one in which CWP is complicated by the additional pathology of large masses of solid tissue within the lung parenchyma. The condition usually occurs after 20 - 30 years in the occupation.

It is associated with breathlessness, clubbing, bronchitis, emphysema and right heart failure. This condition may be due to quartz, coal mine dust plus rheumatoid arthritis (as seen by Dr. A Caplan in 1953 in New South Wales Coal mines). Progressive massive fibrosis is characterized by formation of a mass 3 - 10 cm or more in length in the lung tissue and lying parallel to the pleura : this may cavitate after many years releasing large quantities of black necrotic tissue and dust which is coughed out as an expectorant resembling black ink (melanoptysis). Control measures centre on dust control and early detection of the disease.

In X - rays, 3 stages are seen in simple CWP. First stage - Generalized mottling of the lung through which exaggerated lung markings are seen. Second stage - Mottling becomes very dense and exaggerated lung marking cannot be seen through them. Third stage - Very dense reticulated opacities seen all over the lung. The reticular markings indicate coal dust foci around the tips of the bronchioles. A person suffering from silicosis is both breathless and ill but a person with CWP is breathless but does not look ill. It has been seen that there is a negligible risk of developing CWP over a working lifetime with a dust level below 2mg/cu.m. The basic lesion of CWP is the local macule. Air spaces adjacent to the macule get enlarged, consistent with focal emphysema. A small percentage of miners develop complicated CWP or PMF diagnosed radiologically by the appearance of a density 1 cm or greater. Recent studies suggest that superoxide anion generation by alveolar macrophages may play a role in the lung injury of CWP. The introduction of improved ventilation, water spraying

Fig. - 1 : Methods of Dust Control

Medical Control Personal Control

Proper selection of personsfor dusty tradesPeriodic medicalexaminationEpidemiological analysis

Methods of Dust Control

Environmental Control

Prevention of escape ofdust into atmosphere

Dust control at thesource Control

Personal hygieneRespiratory protection(Dust respirator, Airmask supplied with air)

Change in ProcessRotary diamond drillsin place of pneumaticdrills (in mines placeUse of permanentmould in FoundryUse of plastic sandmixture to form mouldsin foundryUse of dust free flint inglaze of potteries inplace of quartz mixtureWet grinding ofwashing quartz

Control by substitutionSilica carbide/aluminumgrinding wheels insteadof sand stone wheelGround flint replaced bynon-silica substitute inpottery makingSilica free partingcompounds in ironand steel industryAbrasive blastingreplaced by wheel shotblasting

SegregationProper enclosureVentilation general &exhaustReduce magnitude ofair displacement byreview of design ofprocess equipmentPlant layoutSegregating of dust andnon-dusty operations.No crowdingMechanizationGood house keeping

SegregationProper enclosureVentilation general &exhaustReduce magnitude of airdisplacement by reviewof design of processequipmentPlant layoutSegregating of dust andnon-dusty operations.No crowdingMechanizationGood house keeping

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and mechanized equipment has greatly reduced dust levels in the mines. Medical surveillance is the second most important measure to prevent disabling CWP.

Other Lung DiseasesByssinosis : Bronchopulmonary diseases caused by exposure to airborne dust of cotton, flax & soft hemp leads to Byssinosis. It is a chronic respiratory disease characterized by tightness of the chest & breathlessness at work after the weekend or other absence. It is also called ‘Monday Fever’. This is probably due to a histamine releasing substance. In addition to histamine release, exposure to cotton dust causes irritation in the upper respiratory tracts & bronchi, which after prolonged exposures slowly progresses to chronic obstructive pulmonary disease. In early stages there may be decline in FEV1, which may be symptomless in some workers. Within, one or two days, most symptoms tend to disappear except for irritation in the upper respiratory tract. As the disease progresses, the chest tightness is accompanied by breathlessness, the symptoms becoming worse & persisting for a longer time. In its late stages the diseases resembles chronic bronchitis & emphysema, except for the history of chest tightness & decline in ventilatory capacity, characteristically worse at the beginning of the work week. Chest X - rays do not show any specific changes. Prevention includes Pre - placement examination, which should include Chest X ray, VC and FEV1. Periodic medical examination is recommended every year. In groups of workers, a drop of more than 10% in FEV1 during the work shift on the day after the weekend holiday may provide advance warning that workers are liable to develop Byssinosis.

Occupational Asthma : Occupational asthma is a form of lung disease in which the breathing passages shrink, swell, or become inflamed or congested as a result of exposure to irritants in the workplace. Occupational asthma is a lung disorder characterized by attacks of breathing difficulty, wheezing, prolonged exhalation, and cough, which is caused by various agents found in the work place.

Hypersensitivity Pneumonitis : Hypersensitivity pneumonitis is an inflammation of the lung (usually of the very small airways) caused by the body’s immune reaction to small air - borne particles. These particles can be bacteria, mould, fungi, or even inorganic. Hypersensitivity pneumonitis is usually an occupational disease in which exposure to organic dusts, fungus, or moulds leads to acute and over time, chronic lung disease.

Berylliosis : Berylliosis (or beryllium disease) is caused by the inhalation of beryllium particles, dust or fumes. Its symptoms include coughing, shortness of breath, fatigue, weight loss or loss of appetite, fever and sweating. Medical tests may reveal abnormal lung sounds, lung scars, decreased pulmonary function, granulomas (a nodular form of chronic inflammation) and an allergy to beryllium.

Occupational CancersOccupational cancer is any malignancy wholly or partly caused by exposures at the workplace or in occupation. Such exposure may be to a particular chemical (such as ß - naphthylamine), a physical agent (such as ionising radiation or a fibre like

asbestos), a biological agent (such as hepatitis B virus), or an industrial process in which the specific carcinogen may elude precise definition (such as coke production) (13). Common occupational carcinogens include Benzidine, 2 - naphylamine, Arsenic, Beryllium, Cadmium, Chromium, Nickel, Asbestos, Silica, Talc containing asbestiform fibres, Wood dust, Benzene, Trichloroethylene (TCE), Polychlorinated Biphenyls (PCBs) and Ethylene oxide.

PreventionOccupational cancers have two characteristic features namely they are preventable (14) and most occupational carcinogens have first been recognized by clinicians (15).Primary Prevention

Recognising presence of hazards and risks ●Educating management and workforce ●Eliminating exposure by substitution and automation ●Reducing exposure by engineering controls (such as local ●exhaust ventilation and enclosure), changes in handling, and altering physical form in processingMonitoring exposure and maintaining plant ●Protecting workers by means of personal protective ●equipmentLimiting access ●Providing adequate facilities for showering, washing, and ●changingLegislative provisions ●

Secondary Prevention : A secondary approach to prevention consists of detection at an early stage to prevent the further progression of diseases and increased survival by institution of treatment. Screening tests and medical surveillance - for example, exfoliative urinary cytology and skin inspections.

Occupational DermatosesAn occupational dermatitis is one where the inflammatory reaction is caused entirely by occupational contact factors or where such agents are partly responsible by contributing to the reaction on compromised skin. The commonest site is hands followed by forearms. In case of airborne contact dermatitis face may be the prime site on inflammation. Contact dermatitis accounts for at least 60% of occupational skin disease, which, in turn, account for 40 - 70 % of occupationally acquired illness.

Causes1. Physical agents : Heat, Low Humidity, High Humidity, Cold, Pressure, Vibrations, Friction (Coal Mines, Construction Workers) and Occlusion, Presence of Sharp Particles (Fibre Glass), Damage from Minor Lacerations of the Skin, Solar Radiation, Ultraviolet Radiation, Ionizing Radiation.

2. Biological Agents : Bacteria, Viruses, Fungi (Confectioners - Monilia, Sewage Workers, Doctors), Parasites (Miners and Workers in tea gardens - Ankylostomiasis).

3. Chemical Agents : These account for 70% of all occupational dermatoses and include :

Acids ● : HCl, HNO3, H2SO4

Alkalis ● : Hydroxides, Carbonates of Sodium, Potassium and AmmoniumChlorides ● : Sulphuryl Chloride, Arsenic Chloride, Stannous Chloride

• 1278 •

Some examples of substances causing occupational dermatitis are :

Rubber accelerating chemicals, such as Thiurams and ●CarbamatesBiocides - such as Formaldehyde ●Hairdressing chemicals - such as Thioglycolates, ●PhenylediamineEpoxy resin monomers ●Chromates ●Plant allergens - such as Sesquiterpene Lactones found in ●Chrysanthemum

Diagnostic Criteria1. Disease appears during a period of occupational exposure

or within a reasonable period of time after the exposure ceases

2. Occurs first on the exposed part3. Disease has not been present previously4. Disease improves after the termination of exposure5. Disease recurs after exposure6. Morphology of the disease is similar to the well known

cases resulting from similar exposure and other fellows with similar exposure similarly affected.

TypesOccupational dermatitis is commonly of two types Irritant contact or Allergic contact Dermatitis. Others are contact urticaria, rubber latex protein sensitivity and photo contact dermatitis.

Management1. Detailed occupational history2. Evaluation of contact factors3. Patch test followed by recommendation on reducing or

stopping exposure to the offending agent and similar ones.

4. Chemical analysis of environmental materials to determine whether they contain a substance to which the patient is patch test positive.

Prevention1. Primary prevention is aimed at providing appropriate

information and protection.

2. Employer and employee should be aware of the potential risks of exposure

3. Education of need for good occupational hygiene4. Adequate provision of suitable and effective means of

reducing exposure5. Awareness of limitations of personal protection devices6. Engineering or environmental control. Few examples are

given below :Substitution of mineral oil by vegetable oils ●Segregation and mechanical handling of radioactive ●substancesLocal exhaust ventilation - chromium plating ●Good general ventilation ●Good housekeeping - mercury and its compounds ●Safe design of the plants ●Provision of adequate bathing and washing facilities ●Provision of protective clothing ●Periodic environmental survey to ascertain TLV ●Wet methods ●

7. Medical methods

(i) Pre - placement medical examination : careful and detailed history to exclude allergic tendencies such as eczema/ asthma. Such people may not be employed in occupations with sensitizers.

(ii) Standardized Patch Testa) Test substances appropriately diluted. Standardized kits

available.b) Apply the patch to the upper or mid back.c) Leave the patch in place and keep dry for 2 days before

removing.d) Read tests :

The same day that patches are removed ●One additional reading 3, 4, or 7 days after test initially ●applied

e) Grade test reactions according to intensity : 0 = no reaction to 3+ = small blisters

Relate relevance of positive reactions to clinical dermatitis cautiously. Careful history and review of skin exposures must establish significance.

(iii) Treatment : Treatment with barrier / moisturizing creams, topical steroids, oral steroids and antibiotics if required.

• 1279 •

226 Industrial Accidents

Ashok K. Jindal, Leo S. Vaz, Puja Dudeja

The most important industrial hazard due to machinery is the accidental injury. A detailed account of the prevention of industrial accidents is outside the scope of this book. Box - 1 depicts epidemiology of industrial accidents, while Fig. - 1 shows methods of accident prevention.

The first step in any accident prevention programme is elimination of various hazards whilst designing the process. If this is not possible, the next best step would be to control the physical, mechanical and chemical hazards in work environment by suitable engineering design. But when this also is not possible or is not able to give full protection to workers the third line of defence has to be resorted i.e., the personal protective equipments. These protective equipments cannot eliminate hazard or stop an accident taking place. These equipments merely set up a barrier against the hazards thereby preventing or minimizing an injury.

In selection of these equipments, the following points are to be borne in mind :(a) Type of hazard to be faced(b) Selection of right type of personal protective equipment(c) Availability of correct equipment in good condition at the

work spot(d) Training of workers to use the equipment(e) Convincing the workers that the equipment is used will

protect them from hazard(f) Making it a habit with the worker to use the equipment,(g) Degree of protection needed

(h) East and comfort with which it can be used and freedom of movement with equipment which should not hamper performance of the worker

(i) Maintenance of these equipment(j) Periodical check up(k) Good earthing

Safety AuditObjectives(i) Critically evaluate the safety programme(ii) Evaluate the systems to identify and control hazards(iii) Check that the above system meets the statutory standards

and codes of practiceBenefits(i) Strengthening of the Organization safety standard and

programme.(ii) Improve the skill and performance of employee and

managers.(iii) Helps to create group and self awareness and provides

motivation.(iv) Identifies specific deficiencies in the safety programme.(v) Provides timely information before any injury producing

incident occurs.MechanismSafety audit shall be carried out at three levels

(i) Level - 1 : Internal Audit inspection by Safety Officers from within the factory once in every three months.

(ii) Level - II : Audit inspection by a group comprising of 3 officers of the factories in the concerned group, once in a period of six months.

(iii) Level - III : Annual Audit inspection by the Regional Controller of Safety / O.F. Board.

Box - 1 : Epidemiology of Industrial Accidents

Host factors Agent factors Environment factors

Age ●Sex ●Experience and education ●Concomitant disease ●Psychological factors ●Personality Traits/ ●Emotional stabilityWearing unsuitable shoes ●Carrying improper loads ●Faulty stepping ●Not using personal ●Protective measuresPhysical defects ●

Improper planning and ●construction of factoriesMachines ●Faulty design ●Lack of maintenance ●Entanglement of loose ●clothes and hairTransmission of Machinery ●Speed of Work Processes ●Faulty planning ●Boiler explosion ●Dust explosion ●Corrosive materials ●Molten metal and Hot liquids ●Flying solid particles ●Metal grinding ●Stone dressing ●Riveting ●Chipping metal ●Electricity ●Gassing ●

PhysicalOvercrowding ●Defective lighting ●Temperature ●Ventilation ●Humidity ●Radiations from surroundings ●Pressure ●Noise ●Vibrations ●Ionizing Radiation ●Slippery Floors ●Uncovered drains ●

SocialAt work place ●Domestic ●Relationship between ●workers and managementLack of Safety Policy ●

• 1280 •

Fig.

- 1

: P

reve

ntio

n of

Ind

ustr

ial A

ccid

ents

Planning

Legislation

Designand

Constructionof

factory

Collaboration

IndustrialMO

SafetyOfficer

Chemist

IndustrialHygienist

Supervisor

Engineer

PersonnelOfficer

WelfareOfficer

UnionLeader

SocialWorker

ProperTraining

Supervision

EducationofWorkers

onShopfloor

Accident

Investigation

Research

-Engineering

-Medical

HumanBehavior

Training

PersonalProtective

equipment

Guards

PaintingofDangerous

Parts

Maintenance

ClearPolicy

SafetyCommittee

JobAnalysisofeach

Worker

Supervision

TrainingofNew

Worker/trainee

IndustrialFatigue

AvoidLonghours

Posture

PreventingBoredom

Recreation

WelfareServices

Precautionsagainst

toxicFumes,gases

andDustvapours

Substitution

Segregation

ExhaustVentilation

PeriodicMAC

ChecksofEquipment

Lighting

ThermalComforts

Noisecontrol

VibrationControl

RadiationControl

Precautionsagainst

Fire&Electrocution

Goodhousekeeping

Clothing

Dust

Masks

Respirator

ProperWeightlifting

MedicalExamination

PsychologicalTest

PhysicalCheckof

Environments

StatisticsofAccidents

EngineerDesigning/

settingMachinery

Investigationof

Accidents

HealthEducation

Collection&Utilization

ofInformationofSpecial

DangersinIndustry

Methodological

InvestigationofPhysical

andPsychological

Causes

Standardizationof

Statistics

PrescribingsafetyBy-

laws

Research

Publicitymaterial

Encouragesafety

measures

Roleof

management

Processing

Personal

protection

GoodWorking

Environment

Foremanand

safety

IndustrialMO

andsafety

Machines

RoleofILO

PreventionofIndustrialAccidents

• 1281 •

ScopeThe Audit is necessarily very wide ranging in scope and covers all aspects of a company’s operations. Some of the broad areas to be covered for Safety Audit are to study, in detail, the Safety Policy, Process Safety, Fire Safety, Hazards in the processes and their control, Pollution control, Machine guarding, Housekeeping, Material Handling system, Training of workers/supervisory staff and Management personnel, Accident reporting, investigation & analysis, Emergency preparedness and availability of Health, First Aid, Periodical Medical examination.

Accident Investigation : All accidents should be investigated by the concerned Heads of Sections and an unambiguous report sent in Form No. 14. Safety section shall investigate selected accidents involving plants/machineries/chemicals

where accidents are due to unsafe conditions. In case of all serious accidents, a Board of Enquiry to investigate in to the accident shall start investigation immediately on receipt of intimation by visiting the accident spot so that the evidence is not tampered. Photographs may be taken if necessary. The investigations should be towards fact finding and not fault finding. The concerned sections shall not disturb the site until it is cleared by the board of Enquiry of Safety Officer.

Accident Returns & Analysis : The accident statistics indicating details of accidents, man days lost, man hours worked are compiled quarterly. A monthly report on the accidents taking place during the preceding month is also compiled. Any accident taking place in the factory shall be analyzed by Safety Section.

227 Industrial Toxicology

Ashok K. Jindal & Puja Dudeja

Industry uses and manufactures wide variety of substances, which are either known or suspected to cause toxic effects in the persons working with them. Industrial toxicology is concerned with the study of various substances used in industry either as media for processing some other materials or as raw materials or the finished product. The Permissible Exposure Limit (PEL) to a substance is defined as exposure to a maximum time weighed average (TWA) of concentration of a toxicant for an 8 - hour work. The Threshold Limit Value (TLV) is that limit in an environment of a toxic agent or the substance or the deleterious material which when inhaled by a worker for a duration of 8 hours per day for indefinite periods will not cause any harmful effects.

Details of industrial toxicology in respect of common and important toxic substances are being described in this chapter. The general measures of prevention and control are dealt with subsequently.

LeadLead is ubiquitous in industry and poisoning due to absorption of lead and its compounds is still common. Lead is the most commonly used metal in industries because of anticorrosive property. Hazardous process are lead smelting, burning and making paint, painting, welding riveting, battery manufacture, and lead baths connected with heat treatment of metals, specially when carried out in confined spaces. Inhalation of lead dust and fumes is the chief route of poisoning, the next common route is ingestion, cutaneous absorption is rare. It is rapidly absorbed into general circulation when inhaled

and produces ill effects much more rapidly and probably in a more severe from than when ingested. Young persons are more prone to lead poisoning than adult. Lead concentration in the working atmosphere should be kept below 2.0 mg per 10 cu m of air ( 25 - 31).

Symptoms : The commonest manifestations of lead poisoning are blood changes and lead palsy. Lead makes the RBC fragile and causes haemolysis, which results in anaemia with compensatory stimulation of the bone marrow. So immature RBC or reticulocytes appear in the blood. The RBC count is generally below 3 million with haemoglobin under 70 percent (Sahli). In ‘Lead palsy’ there is a typical degenerative neuritis and subsequent fibrosis. In acute lead encephalopathy, there is involvement of the meninges with oedema and increased intracranial pressure. There may be some capillary damage as well. The lead line showing blue discoloration of the margins of the gums is a classical sign. A diagnosis of lead poisoning should be based on clinical finding, biochemical evidence of excessive lead absorption and by evidence of unusual exposure (See Table - 1 and 2).

Prevention : It depends on good housekeeping, personal protection and education of workers and medical supervision for the detection of hazards the occurrence of poisoning followed by its rectification.(i) Exhaust ventilation measures so arranged that whatsoever

position the worker assumes the lead dust and fumes are drawn away from his face.

(ii) Strict periodical inspection of the exhaust system : All ducts and their angles should be cleaned periodically.

(iii) Avoidance of crowding in the workrooms where metallic lead is heated.

(iv) The floor should be impervious to water, and smooth so that no lead dust can accumulate.

(v) The floor should be constantly kept wet & swept before

• 1282 •

and after the day’s work with a vacuum cleaner.(vi) Workers should wear special work clothes which should

be removed before leaving the factory and deposited in specially provided lockers in order to ensure the prevention of contamination of private clothes.

(vii) Suitable respirators against lead dust and fumes should be use and inspected regularly.

(viii) No food, drink and tobacco should be taken in a place where there is a risk of lead poisoning - special rooms should be provided for this in factories.

(ix) Personal cleanliness should be ensured by providing bathing and washing facilities.

(x) Health education to avoid dusts and fumes of lead being inhaled or ingested.

(xi) Medical surveillance : Pre-employment medical scrutiny of the prospective workers in the hazardous process should include the history of previous exposure to lead and elimination of those with a positive history of symptoms of lead poisoning. Quarterly medical examination during employment with attention paid to the loss of weight, gastrointestinal symptoms, weakness of wrist muscles and blood picture, removal from exposure should be followed

by active treatment.Treatment : When lead poisoning is diagnosed, the further exposure should be discontinued, the use of penicillamine and Ca - EDTA, chelating agents, help in bringing down the blood lead levels by promoting lead excretion in urine. A saline purge will help to remove unabsorbed lead from the gut and also will relieve constipation.

Tetraethyl LeadExposure to high concentrations of vapour of leaded petrol, especially in hot weather, is responsible for an acute form of lead poisoning (lead encephalopathy). In industry this hazard occurs by spillage in petrol filling sheds/holds/barges with inadequate ventilation, inhalation from clothing saturated with petrol from spillage and splashing and absorption through the skin, which is relatively sight. In some cases a chronic form of lead poisoning occurs. Proper ventilation of the shed is important. The operation of filling should be carried out in the open air. Exhausted fans may be necessary. Special precautions must be adopted when containers are loaded in the holds of the barges. Only containers in sound condition should be accepted for loading and care should be taken in the

Table - 1 : Manifestations of Lead Poisoning

System Evidence of absorption Evidence of incipient poisoning Evidence of definite poisoning

General appearance

Restive, moody, easily excited, emotional, lead line

Pallor, Leadline, Jaundice Anemia, Leadline, Jaundice, Emaciation, “Premature ageing”

Digestive System

Persistent Metallic taste, slight anorexia slight constipation

Metallic taste, definite anorexia, slight colic, constipation

Metallic taste, increasing anorexia, nausea and vomiting, marked colic, rigid abdomen marked constipation, blood in stool

Nervous System

Irritability, uncooperativeness

Slight headache, insomnia, slight dizziness, palpitation, increased irritability, increased reflex

Severe headache, increased insomnia, increased dizziness ataxia, confusion, marked reflex changes, tremor, fibrillary twitching, neuritis, visual disturbances, encephalopathy hallucinations, convulsions, coma paralysis.

Miscellaneous -Muscle soreness, easily fatigued General weakness, arthralgia,

hypertension

Urine examination

Abnormal lead content Abnormal lead content, Albumin, Casts

Abnormal lead content, Albumin, Casts, Porphyrinuria, Haematuria

Blood changes

Polycythemia, polychromatophilia, increase platelets, reticulocytosis, abnormal blood lead

Normal red cell count and haemoglobin, reticulocytosis 50 - 100 stippled cells per 100,000 RBC, abnormal blood lead

Decrease in haemoglobin, decrease in RBC, increase in cells showing basophilia, anisocytosis and poikilocytosis, decreased platelets, increase in blood lead

Table - 2 : List of Bio-Chemical Tests

Test Normal Population Acceptable absorption in occupation

Excessive absorption occupation with

signs & symptoms

Blood lead 10μg/dl 75 μg/dl >80μg/dl

Urinary lead 10-65μg/g Cr Upto-150 μg/g Cr >150 μg/g Cr

Zinc protoporphyrin 16-35 μg/dl Upto 100μg/dl >100 μg/dl

Urinary delta aminolaevulinic acid 5 mg/g Cr 6-20 mg/g Cr >20mg/g cr

• 1283 •

storage of the containers. The holds of the barges /tanks should be provided with adequate ventilation. Short shifts at frequent intervals during the work and overall turnover of the labour, so that each man is employed for one week in four on this work, are essential preventive measures. Other precautions are the same as have been described under lead poisoning with the current trend on use of unleaded petrol; it is presumed that toxicity due to this cause will be on the decline.

PhosphorousWhite Phosphorus (WP)White phosphorus (WP) is being used in smoke producing ammunition. After white phosphorus exposure burnt skin is washed with 5 % sodium bicarbonate and 3 % copper sulphate in 1 % hydroxy ethyl cellulose. Phosphorus particulars become coated with black cupric phosphide allowing easy identification. Copper sulphate also decreases rate of underlying tissue. Since blackened particles continue to elicit tissue injury, they can be removed. Of late, copper sulphate is found to be toxic and systemic copper poisoning can manifest as vomiting, diarrhea, oliguria, haematuria, hepatic necrosis and cardio - pulmonary collapse.

MercuryMercury FulminateIt is a brownish yellow, heavy, crystalline solid prepared by the action of alcohol on mercuric nitrate. The chief hazard is dermatitis affecting those who are employed in filling operations where a fine dust is raised, which comes in contact with the naked skin. The susceptibility of some individuals may not enable them to withstand exposure even for a day. The exposed parts of the body become erythmatous accompanied by violent itching, swelling and oedema of the face, eye - lids, ears, neck and forearms. Teeth become black owing to the formation of mercuric sulphide. Cleanliness of the plant is important. All precautions as for a lead factory should be taken. Exhaust ventilation with fitting overalls, aprons, rubber gloves, and if necessary respirators as well. Additional hand washing facilities should be provided (26 - 31).

ChromiumChromic Acid and bichromates of sodium and potassium are used in chromium plating of metals, manufacture of explosives and for tanning of leather, characteristic chrome ulcers occur on nail beds and the nasal septum. They are small, deep ulcers varying in size from the head of a matchstick to the end of a lead pencil. The tissues around the ulcers are heaped up and are covered by crusts. They may cause perforation of the nasal septum. The ulcers are as rule not painful but heal very slowly (25 - 31).

PreventionMechanical lateral exhaust ventilation should be provided for the removal of the vapour and spray at the point of origin. The floor of rooms containing chrome baths should be impervious, maintained in good condition and flushed out daily. Suitable rubber gloves, aprons and other protective clothing should be provided and maintained properly. Water taps should be installed in workplaces, to enable the workers to wash hands

frequently. Shower bath and a change of clothing should follow the day’s work. All cuts, abrasions and other injuries on hand and forearm should be protected by adhesive strapping before starting work. The forearm should be inspected twice a week and any breach of continuity of the skin should be immediately reported to the factory doctor. A protective ointment should be applied in the nostrils.

Metal Fume FeverIt is an transient illness and is commonly known as ‘Brass Founders Ague’ ‘Zinc Fever’ or ‘Metal Chill’. It follows the inhalation of high concentrations of finely dispersed zinc or brass fumes, usually in the form of oxides. After heavy exposure, the nose and throat feel dry and sore giving rise to a dry cough. In a few hours, the symptoms appear. There is shivering which may last for some time and this is followed by profuse perspiration, the picture simulating that of an attack of malaria. Considerable prostration follows the attack, but by the next morning recovery is almost complete. Some degree of insusceptibility is produced by low - grade inhalation but is lost in 48 hours. Workers therefore, are likely to suffer more on Monday morning; Metal fumes should be eliminated by proper exhaust ventilation. When conducting replacement or transfer medical examinations, cases with a history of chronic bronchitis, asthma or any other respiratory trouble should be withheld.

Mineral OilsMineral oils are insoluble and soluble. The insoluble ones are used mainly as lubricants for cutting tools and the soluble ones are used as cooling agents. Cutting oils have the property of defattening the skin. They also plug the pores of the skin and form comedones. After some days of use they may contain steel slivers, which may injure the skin and thus start dermatitis affecting the forearm and thigh, small blackheads due to blocking of the sebaceous glands appear in these areas.

PreventionCleanliness of persons, their clothes and machines should be ensured by the provision of adequate washing and shower bath facilities. suitable industrial cleaners should be placed at convenient location in the washroom. Clean rags or cotton waste free from silver should be provided. Time should be allowed for workers to carry out thorough cleansing, change of clothes and dressing. Those who give a previous history of dermatitis should be excluded by pre placement examination. Persons suffering from seborrhea, acne and excessive sweating should be prohibited from employment appear, the person should be temporarily withdrawn from the process and re - employed when the skin condition clears up.

TreatmentThe treatment is usually by soothing lotions or cream like calamine. Barrier creams may help in getting the skin of the beginners slowly conditioned to the contact with cutting oils but cannot serve as a permanent protective measure for persons whose skins are excessively sensitive.

BenzeneThis is colourless aromatic hydrocarbon with a characteristic

• 1284 •

pleasant smell. It is extensively used as a solvent and a starting material in the synthesis of numerous chemicals (25, 26, 32 - 36).

Acute PoisoningClinically, acute poisoning is of three general types, depending upon the severity of its anaesthetic effects on brain centers. Very high concentrations of benzene inhalation may result in unconsciousness, followed by death from respiratory failure. With somewhat lower concentrations, there may be dizziness, weakness, apprehension, collapse and unconsciousness. Death may occur from respiratory failure.

Chronic PoisoningThe haemopoetic system is mostly affected but degenerative changes are also observed in the kidneys and heart. There is weakness, dizziness, rapid pulse, persistent headache, malaise, loss of appetite, shortness of breath, undue fatigue, decreased resistance to infections, and ulcers in the throat. Due to decrease in platelets, there is bleeding from the mucous membrane and haemorrhage in tissues. Macrocytic anaemia gives more reliable indication of the poisoning than leucopenia, especially in the early part of the disease.

PreventionThe ventilation of the workroom should be improved by mechanical exhaust ventilation. A monthly examination of the employees should be carried out including a complete blood count, and findings recorded in a special register. There should be a rotation in duties of the personnel. Worker’s showing an altered blood picture should be removed from exposure. They should report for medical examination, if bleeding from the nose, gums or other mucous membranes is noticed. Toluene, Xylene, Cyclohexane or trichloroethylene can be used as comparatively safer and satisfactory substitutes for benzene.

Trichloroethylene (Trilene)It is colourless liquid with chloroform like odour. It is largely used in the metal industry as a degreaser. When the exposure is sudden, the worker may die and the post - mortem examination may reveal oedema of the lungs and petechial haemorrhages. Fatty degeneration of the liver, kidneys and heart is present if death is delayed. Repeated exposure affects the central nervous system leading to paralysis of the hypoglossal nerve, sensory fibres of the fifth nerve, second cranial nerve and polyneuritis in the limbs. Mild poisoning may cause various grades of unconsciousness as occurred in the past in laundry workers. Trichloroethylene should be used only in closed systems or in rooms with a downward exhaust ventilation system. Workmen with dry and fissured skin should not be permitted to handle the chemical. Inhalation of a mixture of 95 percent carbon dioxide is of great value in the treatment of poisoning. Artificial respiration may be necessary ( 25,26,31,32).

Carbon - MonoxideIt is a colorless and odourless gas formed from the incomplete combustion of materials containing carbon. It is encountered in various industries such as foundries, gasworks, ovens, blast furnaces and in automobile garages. It is a chemical asphyxiant. It forms a relatively stable compound, carboxyhaemoglobin

when it combines with haemoglobin, as its affinity for the haemoglobin is about 300 times that of oxygen ( 25,26 ).

SymptomsAcute poisoning causes a sudden onset of unconsciousness, rapidly developing cyanosis and death. Initial symptoms of sub acute carbon monoxide poisoning, which are more likely to be encountered in industry than the acute poisoning are shortness of breath palpitation on exertion accompanied by slight headaches which tend to increase in severity. With the increased concentration of this gas in the blood, judgment becomes fogged and the affected individual may not realise his own danger. If the exposure continues, mental aberration is followed by unconsciousness resulting in death from respiratory failure. Chronic poisoning shows all these symptoms coming on gradually and then continuing for longer periods.

PreventionMinimising its leakage by ensuring efficient ventilation, and finally by observing the rules of personal protection can prevent carbon monoxide poisoning. No person should be allowed to work single handed in a place where there is a danger of production of this deadly gas. No workman should enter or approach a place until the gas has been flushed out by fresh air and a suitable breathing apparatus issued. Safety posters in common languages should be displayed at strategic points explaining the deadly nature of symptoms of poisoning and means of rescue and first aid. Workmen should be given practice drill in rescue operation, artificial respiration and resuscitation. A cylinder containing a mixture of 95 percent oxygen an 5 percent carbon dioxide with a close fitting mask, should be available at all times for immediate use.

TreatmentThe victim should be removed immediately into fresh air and should not be made to walk even if he is conscious. The oxygen and carbon dioxide mixture should be administered or oxygen should be administered under positive pressure if available. If the breathing has stopped or is shallow, artificial respiration must be started and continued until normal breathing returns. If the heart has stopped beating, cardiac massage and stimulants should be given. Absolute rest in bed and warmth are essential. A close vigil should be maintained because of the tendency to relapse. Artificial respiration, administration of oxygen - CO2 mixture and cardiac massage should not be stopped until it is quite certain that heartbeat can not be revived.

Hydrogen CyanideIt is colourless gas with a penetrating bitter almond odour, Sodium and potassium cyanide baths used in the heat treatment of steel and iron are potential health hazards (25, 26).

SymptomsHydrogen cyanide like carbon monoxide is a chemical asphyxiant and prevents the tissue from using the oxygen carried in the blood. When inhaled in high concentration it caused sudden collapse and almost immediate death. In lower concentration symptoms are delayed; the patient complains of headache, dizziness, vomiting, general weakness; slow and irregular respiration and pulse is almost imperceptible. There

• 1285 •

is a smell of bitter almonds in the breath, and if inhalation continues for some time coma supervenes, followed by death from respiratory failure.

PreventionEfficient plenum and exhaust ventilation, respiratory devices, protective hood and respirators ensure safety.

TreatmentImmediate first aid measure comprises of removing the patient to fresh air, keeping the patient warm and at rest and removing contaminated clothing. Contaminated skin is washed well with water. Treatment consists of inhalation of amyl nitrite for 15 - 20 secs every 2 - 3 mins along with oxygen inhalation and artificial respiration. If patient is comatose or becomes drowsy then Dicobalt edetate ( 300 mg in 20 ml glucose sol) should be given by slow IV injection over 3 - 4 mins. If there is no return to consciousness then give sodium thiosulphate (12.5 gm in 25 ml of 50 % sol) IV over 5 - 6 mins. If the symptoms reappear or persist, half the dose of the antidotes should be repeated one hour later. If cyanide has been swallowed, gastric lavage is essential.

Nitrous FumesThe chief constituent of nitrous fumes are nitrous oxide, nitric acid and two forms of nitrogen dioxide, NO2, N2O4; the last two lend a brown colour to the fumes. Nitrous fumes are present in industries where sulphuric & nitric acids and explosives are manufactured. The fumes are also a hazard in certain operations e.g. welding, metal cleaning and electroplating. Toxicologically nitrogen dioxide NO2 is the most important of the oxides of nitrogen (25, 26).

SymptomsThe fumes should be controlled at the point of origin by efficient general ventilation and by local exhaust ventilation. Isolation of the offending operation is helpful where the process does not yield readily to the above measure of control. Respiration protective devices such as chemical filter respirator are justified as a last resort when all other measures of control have proved ineffective. These masks need periodical examination and proper maintenance. The education of the worker in the use of the respirator is of utmost importance.

PreventionThe fumes should be controlled at the point of origin by efficient general ventilation and by local exhaust ventilation. Isolation of the offending operation is helpful where the process does not yield readily to the above measure of control. Respiratory protective devices such as chemical filter respirators are justified as a last resort when all other measure of control has proved ineffective. Thee masks need periodical examination and proper maintenance. The education of the worker in the use of the respirator is of utmost importance.

AlkaliesThe alkalies used in industry are chiefly ammonia, potassium and sodium hydrates. The industrial hazard form ammonia is invariably due to the accidental escape of the liquid or gas. It is very irritating to the upper respiratory passages and

may give rise to pulmonary edema. Burns may follow the splashing of ammonia and other alkalies, especially in the eyes. Prevention is achieved by taking precautions to obviate the except of ammonia and the use of goggles or eye shields. If splashing occurs, frequent irrigation of eyes by a 4 percent solution of ammonium chloride should be ensured to reduce the fixed alkalies. Penicillin droops or ointment should follow irrigation.

AcidsThe common acids used in industry are sulphuric, nitric and hydrochloric acids. When splashed into the eyes they cause severe burns of the cornea and conjunctiva. Prevention of splashing by protective devices, training of workers in work methods and personal protection are important precautions. Tubs full of water ‘plunge baths’ should be kept in the sections which involve the risk of chemical burns so that the affected individual can immediately plunge into it for washing the chemical without vigorous rubbing. In cold weather, the water bath should be kept at 38°C (about the body temperature) during working hours. A number of ointments containing 3 percent boric acid solution should be placed in strategic places and workmen should be taught how to irrigate the eyes immediately. Splashing clean water into the eyes is also helpful. Arrangements should be made for the mechanical transport of carboys containing acids covered with baskets and handled as little as possible.

General Measures for Prevention / Reduction of Hazards : Industrial ToxicologyEngineering MeasuresGeneral rules for prevention/reduction of hazards from dangerous and obnoxious substances are as under :

(a) Substitution : Wherever practicable the use of offending substances should be prohibited. Failing that, a harmless substance should be substituted for the harmful one e.g. the use of yellow phosphorus substituted by phosphorus sesquisulphide in the match industry, sand - blasting may be substituted by shot blasting, and acetone may be issued in place of benzol as solvent.

(b) Total enclosure : Through airtight enclosure, personal contact with harmful substances such as dusts, fibres, fumes, gases, mists or vapours can be prevented.

(c) Local exhaust Ventilation : Where an airtight apparatus cannot be used, the harmful products should be removed at or near their point of origin by means of fume chambers or suction hoods properly connected to efficient exhaust systems.

(d) Dust Suppression : Where practicable the material should be used in a moist or wet state to prevent the evolution of dust e.g. lead

(e) Duration of Exposure : Limitation of the duration of exposure or employment should be compulsory in certain trades e.g. in radioactive processes.

(f) Segregation : Segregation of process involving toxic agents i.e radioactive material is segregated. Segregation is also coupled with mechanical handling.

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(g) Use of wet methods : Dry processes lead to cloud of dust. Wet methods can prevent this.

i. Wetting basic material : when painters scrap the lead paint, repeatedly wetting sand paper in water.

ii. Periodic environmental sprays : for humidification in mines and mills

iii. Use of hydraulic mills in mines

(h) Good housekeeping : The golden rule is that there is a place for everything and everything has a place.

(j) Good general ventilation : It dilutes the substance in work environment.

(k) Provisioning of control equipment : Equipment like continuous carbon monoxide detectors and carbon monoxide detection tubes.

(l) Periodic environmental surveys : These will help in detection of any leak at an early stage. Threshold limit value of a substance should not be exceeded.

(m) Safe plant design : Safety engineers should be involved in the construction of the plant.

Personal control measures(a) Protective clothing : It includes the following -i. Helmetsii. Gogglesiii. Earplugsiv. Gowns and apronsv. Shoesvi. Personal monitoring equipment like dosimetervii. Respirators

Medical control measures(a) Medical examinationi. Pre placement medical examination - before one is

employed in a particular job.ii. Periodical medical examination.iii. Medical examination of susceptible groups - young people,

old age, people with anaemia, malnutrition, females.iv. Medical examination before leaving the job or work.v. Medical examination of persons joining after a periods of

sickness.vi. Medical examination for early detection of cases and

treatment.(b) Good record keeping : It helps both in early detection and research.

(c) Periodic environmental surveys : Done by medical and safety personnel.

(d) Health education : By far the most important safety factor is the cooperation of the worker in obeying the given safety orders and instructions. Too often the safety notices / posters are couched in purely negative terms; the worker is exhorted not to perform one or other action and is left in doubt as to the reason for prohibition. A positive approach has been found to be more effective. If the notices give an indication of the hazard to which the workman would be exposing himself, there could be less temptation for disobeying the restrictions.

Legislative Measures(a) Restriction of Employment : Children below 14 years are not permitted to work in any industry. Women and young persons between 15 - 18 years are prohibited from working in hazardous industries. Women are prohibited from working underground in a mine.

(b) The Factories act, 1948 modified in 1987 lists diseases which are notifiable.

228General Measures of Prevention & Control of Occupational Diseases

Ashok K. Jindal & Puja Dudeja

Measures of Prevention and Control of occupational diseases are shown in Fig. - 1.

Engineering measuresGeneral rules for prevention/reduction of hazards from dangerous and obnoxious substances have been discussed under the heading of safe design of building. However other

methods for prevention of occupational hazards are given as under :

Substitution : Wherever practicable the use of offending substances should be prohibited. Failing that, a harmless substance should be substituted for the harmful one e.g. the use of yellow phosphorus substituted by phosphorus sesquisuphide in the match industry, sand - blasting may be substituted by shot blasting, and acetone may be used in place of benzol as solvent.

Total enclosure : Through airtight enclosure, personal contact with harmful substances such as dusts, fibres, fumes, gases, mists or vapours can be prevented.

Local exhaust Ventilation : Where an airtight apparatus cannot be used, the harmful products should be removed at or

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near their point of origin by means of fume chambers or suction hoods properly connected to efficient exhaust systems.

Fig. - 1 : Measures of Prevention and Control of occupational diseases

Prevention ofoccupational

diseases

Engineering measures

Medicalm

easuresLegislative measures

Pers

onal

prot

ectiv

eeq

uipm

ent

Dust Suppression : Where practicable the material should be used in a moist or wet state to prevent the evolution of dust e.g. lead.

Duration of Exposure : Limitation of the duration of exposure or employment should be compulsory in certain trades e.g. in radioactive processes.

Segregation : Segregation of process involving toxic agents i.e radioactive material is segregated. Segregation is also coupled with mechanical handling.

Use of wet methods : Dry processes lead to cloud of dust. Wet methods can prevent this.i. Wetting basic material : when painters scrap the lead paint,

repeatedly wetting sand paper in water.ii. Periodic environmental sprays : for humidification in

mines and mills.iii. Use of hydraulic mills in mines.Good housekeeping : The golden rule is that there is a place for everything and everything has a place.

Good general ventilation : It dilutes the substance in work environment.

Provisioning of control equipment : e.g. continuous carbon monoxide detectors and carbon-monoxide detection tubes.

Periodic environmental surveys : These will help in detection of any leak at an early stage. Threshold limit value of a substance should not be exceeded.

Safe plant design : Safety engineers should be involved in the construction of the plant. A positive approach has been found to be more effective. If the notices give an indication of the

hazard to which the workman would be exposing himself, there could be less temptation for disobeying the restrictions.

Medical Control MeasuresMedical examination

Pre placement medical examination : It is done before one is employed in a particular job i.e. at the time of entry into an employment and includes a detailed history followed by complete physical examination and laboratory/ radiological investigations of the individual. It helps in rejecting the individuals who are unfit and also helps in placement of the worker to the right job so that there is maximum productivity and at the same time it is less detriment to worker’s health. It also gives a baseline for various parameters which can be used for future comparisons.

Periodical medical examination : This involve checkup of workers at periodic intervals for early detection and treatment of cases. The frequency and content of this examination depends upon the occupational exposure. Ordinarily the workers are examined once a year. However, monthly examination is recommended in case workers are exposed to toxic substances as lead, radium etc.

Medical examination of susceptible groups - young people, ●old age, people with anemia, malnutrition, females.Medical examination before leaving the job or work. ●Medical examination of persons joining after a period of ●sickness.Medical examination for early detection of cases and ●treatment.

Good Record Keeping : It helps both in early detection and research. Records also play an important role in planning, development and efficient operation of an occupational health service. It also helps in planning of preventive services in an industry.

Periodic Environmental Surveys : This includes survey of the working environment in form of temperature, lighting, ventilation, humidity, noise, cubic space, air pollution and sanitation which have an important role in the health of the worker. It is done by medical and safety personnel. These surveys also include study of raw materials, the process and manufactured products.

Health Education : Health education about the process, handling of raw material, correct use of protective devices has a lot of impact in prevention of occupational diseases. The aim is to assist the worker in his process of adjustment to the working, home and community environment. It also includes guiding the worker about various legislations available and social security schemes existing for the benefit of workers.

Personal Protective Equipment (PPE)Personal protective equipment is designed to protect the worker from health and safety hazards that cannot practically be removed from work area. Personal protective equipment protects many parts of body including eyes, face, head, hands, feet, and ears.

Head Protection : Helmets /Hard hats protect from impact and penetration caused by objects hitting head. They also give you

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limited protection from electrical shock or burns.Eye Protection : Goggles give eye protection when working with : molten metals, liquid chemicals, hazardous gases or flying particles.

Ear Protection : Ear protection consists of earplugs and earmuffs. These should be used when the sounds in work area are irritating, sound levels reach 85 decibels or higher for an 8 - hour time period or there are short bursts of sound that can cause hearing damage.

Hand Protection : Gloves give protection against severe cuts or lacerations, severe abrasions, punctures, chemical burns, thermal burns, and harmful temperature extremes.

Foot Protection : Foot protection is important to prevent injuries in case a heavy or sharp object falls on foot or when the worker can step on an object that could pierce his shoe.

Respiratory Protection : Masks (filter/gas/ air purifying respirator) should be used to prevent inhalation of toxic gases into the lungs.

Legislative MeasuresLabour protection for the working people in India is available under various laws enacted by the Parliament as well as the State Legislatures. The Preamble of the Constitution of India guarantees its citizens justice - social, economic and political; liberty of thought, expression, belief, faith and worship; equality of status and opportunities and fraternity, dignity of individual and dignity of nation. The organized sector workers which constitute about 7% of the total workforce of about 400 million in the country are covered under various legislations providing social security to these workers. The major legislations providing social security to these workers are : the Employees’ State Insurance Act, 1948 and the Employees’ Provident Fund & Miscellaneous Provisions Act, 1952 etc. These two legislations provide for medical and health insurance and provident fund & pension to the workers respectively. The Factories act and ESI act have been dealt in detail under social security.

229 Ergonomics

Leo S Vaz

‘Ergonomics’ is derived from two Greek words ‘Ergon’ meaning work and ‘Nomos’ meaning principles or laws. Ergonomics is the Science of Work. Ergonomics is essentially fitting the workplace to the worker. The better the fit the higher the level of safety and worker efficiency. It takes account of the worker’s capabilities and limitations in seeking to ensure that tasks, equipment, information and the environment suit each worker. The anticipated benefits of good Ergonomics are :

Improved health and safety by reducing work - related ●injuries and disorders;Improved comfort, morale and job satisfaction; ●Improved productivity and reduced workers’ compensation ●costs and employee turnover.

Basic Ergonomic PrinciplesTo assess the fit between a person and their work, ergonomists consider :

The job being done and the demands on the worker; ●The equipment used (its size, shape, and how appropriate ●it is for the task);The information used (how it is presented, accessed, and ●changed).

Currently, the focus of ergonomics is to minimize work stressors, both physical and environmental to reduce the potential for bodily harm. The basic work stressors that promote repetitive

or cumulative injuries include excessive repetition, forceful movements, and awkward movements and postures. General ergonomic principles help us to control these work stressors.a) Repetitive tasks may not require much muscular effort,

but the velocity and range of the movements can cause muscles to fatigue quickly as the muscle never completely relaxes and never completely contracts. With insufficient rest time, recovery of micro - trauma to the muscles, tendons and joints is not complete. Gradually, injury builds until swelling and pain begin to limit activity.

b) Forceful movements require excessive tension or pressure on the tissues of the body, increasing muscular effort, reducing circulation to the body’s tissues, and causing muscles to rapidly fatigue.

c) Awkward movements and postures place biomechanical stresses on the joints, muscles and tendons, causing friction and inflammation at the stressed sites, reducing the body’s ability to perform work efficiently and comfortably.

Work - Related Musculoskeletal Disorders (WMSDs)These are MSDs that are caused or made worse by work methods and environment. They occur when the physical capabilities of the worker do not match the physical requirements of the job. Common MSDs are Tendonitis, Epicondylitis (Tennis or Golfer’s Elbow), Bursitis, Trigger Finger, Carpal Tunnel Syndrome, and Back Strain. Work - related MSDs are also known as Repetitive Strain or Stress Injury (RSI) Repetitive Motion Injury (RMI), Cumulative Trauma Disorder (CTD), Overuse Syndrome or Activity - related Pain Syndrome.

Causes of MSDs : The characteristics of a job which put a worker at risk for MSDs are :

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jobs may suffer from bursitis at the knee.

Back Pain and Work : Low back pain is common in the general population, and is a common symptom in workers whose jobs involve manual handling. Although the aetiology of back pain is complex, studies have shown that repetitive overuse and postural factors resulting from systems of work are associated with increased prevalence rates. It is not merely a requirement to lift heavy loads in jobs that leads to an increased risk of back pain; the prolonged maintenance of abnormal postures also causes marked increases in pressures on the spine because of the protective responses of the supporting muscles Consequently, guidelines on manual handling should not merely focus on weights to be lifted, but should also include an assessment of the associated ergonomics.

The handling of load may involve pushing and pulling as well as lifting. Risks of injury to the back or upper limbs are dependent not only on the weight lifted, but also on the posture needed for the lift. Lifting with the back outside of its normal range of movement places stresses on the soft and bony tissues of the spine. The majority of injuries to the back are due to damage to the soft tissues rather than the intervertebral discs, but the symptoms of pain, restriction of movement and disability are the same. Prevention of injury involves eliminating or modifying tasks, and providing lifting aids and training in safe lifting techniques.

Employers should minimize the risks to workers by avoiding lifting and handling manoeuvres except where they are unavoidable. The use of lifting aids and the provision of training are both important risk - reducing measures. There is increasing evidence that psychological risk factors are also important with respect to both the development of low back pain and the occurrence of chronic low back pain. The identification of these risk factors is a necessary component of a holistic risk assessment.

Pregnancy and Ergonomics : A number of studies have looked at the risk to the mother and foetus from physically tiring work and strenuous exercise. The former has a reported association with amenorrhoea, and the latter may lead to an increased risk of abortion, stillbirth and foetal growth retardation. The ergonomic aspects of the developing pregnancy and the resulting reduced flexibility and movement also need to be taken into account when assessing the job, and different recommendations may be appropriate at different stages of the pregnancy.

Prevention of MSDs : The principles involved in prevention of MSDs lies in good Ergonomics and the motto ‘Work Smarter, Not Harder!’ This can be achieved by the following principles :

Work in neutral postures ●Reduce excessive force & repetition ●Keep everything in easy reach and at proper heights ●Keep warm ●Minimize static unsupported postures and pressure points ●

Methods of Reducing Repetition are :a) Break up the repetitive components of a job.b) Switch frequently between tasks.c) Find a different tool that makes the job easier.d) Let the tool or automation do the work instead of the

(a) Repetition : Performing the same motion or group of motions excessively.

(b) Awkward Postures or Postures outside of neutral : Neutral is the optimal position of each joint that provides the most strength and control.

(c) Static Postures : Holding the same position or using the same muscles for extended periods of time.

(d) Cold Temperatures : Working in environments below 68°F can cause nerve damage.

(e) Forceful exertions : A strong physical exertion produces tension by muscles and is transmitted through tendons.

(f) Vibration : Single Point Hand and Arm exposure results from vibrating objects such as power tools.

Whole Body exposure to vibration results from vehicles such as forklifts, cranes, trucks, buses subways and aircraft.

(g) Compression : Soft tissue is compressed between the bone and a hard or sharp object.

(h) Poor work-Station design : It is a risk factor for the development of upper limb disorders. The computer mouse is one of several input devices used with today’s IT, usually with a standard keyboard. Several reports have appeared in the literature of upper limb disorders such as tenosynovitis, lateral epicondylitis and myofascial syndrome resulting from mouse use. The use of mouse results in abduction and flexion at the shoulder, flexion of the elbow and resting of the wrist on the mat along with ulnar deviation for standard tasks. The prevention of problems involves ensuring that the user handles the mouse within his or her normal zone of comfort.

Signs and Symptoms of MSDs : Common Signs and Symptoms of MSDs are Painful aching joints, muscles, tingling or numbness, fingers or toes turning white, Shooting or stabbing pains, Swelling or inflammation, Stiffness or difficulty moving, Burning sensation or Pain during the night.

Carpal Tunnel Syndrome : Carpal tunnel syndrome is associated with exposure to some workplace hazards. Clinically diagnosed carpal tunnel syndrome has been reported to occur in textile and other industrial workers. Pressure on the median nerve as it passes under the flexor retinaculum may lead to the development of a clinical picture compromising pain and paraesthesiae in the thumb, index and middle fingers, which is often worse at night. Wasting of the small muscles of the hand supplied by the median nerve may occur if the condition remains untreated for some time. Nerve conduction studies are often used to assist the diagnosis. Probably the main occupational hazard is repetitive movements of the wrist, although exposure to hand - arm vibration is also thought to be important Surgery to decompress the median nerve may be required to relieve symptoms or preserve function in the hand.

Pre - Patellar Bursitis : Occupational disorders due to repetitive strain are not new. Coal miners, for example, suffered from ‘beat’ conditions. Repeated kneeling and crawling could lead to the development of inflamed pre - patellar and pre - tibial bursae. Beat knee is a combination of haemorrhagic bursitis and pyogenic infection. This condition arises as a result of manual labour causing excessive pressure or friction in the area of the knee. Workers who have to kneel repeatedly in their

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body.e) Introduce leisure activities that have different physical

demands than work activities.Methods of Reducing Force : To reduce the force or exertion required to perform specific activities, use the appropriate tool for the job and maintain tools in good working order. For example, blades should be kept sharp; use longer handles for better leverage; use clamps to hold parts instead of holding with the other hand. A slippery surface requires extra grip strength to hold the object; Avoid sudden impact, jerking, or sudden start - stop movements; when lifting or moving objects, keep them close to your body; push rather than pull.

Methods of Reducing Awkward Positioning & Improving Posture : Proper posture ensures that one keeps reaching to a minimum. This can be done by assuring proper fit of the chair. There should be support for the lower back. Height should be adjustable in relationship to the work surface so that the shoulders are relaxed and the elbows are positioned at the side of the body (in - line with the shoulders). The work should be positioned at a height that allows the elbows to be open slightly greater than 90 degrees. A foot - rest should used when necessary. The work should be positioned directly in front of the body to avoid excessive reaching or turning. Frequently used items should be within an easy reach. Tools that fit the hand well and/or are shaped to help maintain the neutral wrist position should be used. One of the best ways to prevent injuries is to keep a relaxed and neutral posture while working. For those who work at a desk or on a computer, the forward head and rounded shoulder posture is prevalent. However the following are recommended :

The head should be upright with the neck relaxed. ●The monitor should be at a height that allows you to view ●it directly in front of you, not looking up or looking down or to one side or the other.

Use a copy holder if you work input information from hard ●copies.The ears, shoulders and elbows should be in vertical ●alignment.The shoulders should be relaxed, not elevated. ●Arm rests are optional. If you do use arm rests, position ●them at a height that does not push your shoulders towards your ears.The keyboard and most work should be positioned at a ●level just slightly below elbow level. However, depending on the type of work, this may need to be adjusted.The wrists should be in the neutral position flat and ●straight. They should not be bent forward or back, or angled to one side or the other.The fingers should be relaxed. Do not pound on the ●keyboard. Use the lightest touch possible to activate the keys or any tool control.

Seating in the Workplace : Ideally, seats should be personal to the individual worker and move with him or her where necessary, but where this is not possible, adjustable seating should be provided at every workstation. The lumbar region needs to be supported to decrease disc pressure. Providing both a seat back that inclines backwards and has a lumbar support is critical to prevent excessive low back pressures. The combination which minimizes pressure on the lower back is having a backrest inclination of 120 degrees and a lumbar support of 5 cm. The 120 degrees inclination means the angle between the seat and the backrest should be 120 degrees. The lumbar support of 5 cm means the chair backrest supports the lumbar by sticking out 5 cm in the lower back area. Another key to reducing lumbar disc pressure is the use of armrests. They help by putting the force of your body not entirely on the seat and back rest, but putting some of this pressure on the armrests. Armrest needs to be adjustable in height to assure shoulders are not overstressed.

230 Physical Working Environment

Leo S Vaz & Ashok K. Jindal

NoiseHigh levels of occupational noise remain a problem in all regions of the world. Although noise is associated with almost every work activity, some activities are associated with particularly high levels of noise, the most important of which are working with impact processes, handling certain types of materials, and flying commercial jets. Occupations at highest risk for NIHL include those in manufacturing, transportation, mining,

construction, agriculture and the military. The review of the literature indicates that noise has a series of health effects, in addition to hearing impairment. Some of these, such as sleep deprivation, are important in the context of environmental noise, but are less likely to be associated with noise in the workplace. Other consequences of workplace noise, such as annoyance, hypertension, disturbance of psychosocial well - being, and psychiatric disorders have also been described. For occupational noise, the best characterized health outcome is hearing impairment.

Effects of NoiseThe first effects of exposure to excess noise are typically an increase in the threshold of hearing (threshold shift), as assessed by audiometry. This is defined as a change in hearing

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thresholds of an average 10 dB or more at 2000, 3000 and 4000 Hz in either ear (poorer hearing). NIHL is measured by comparing the threshold of hearing at a specified frequency with a specified standard of normal hearing, and is reported in units of decibel hearing loss (dBHL). Threshold shift is the precursor of NIHL, the main outcome of occupational noise. It corresponds to a permanent increase in the threshold of hearing that may be accompanied by tinnitus. Because hearing impairment is usually gradual, the affected worker will not notice changes in hearing ability until a large threshold shift has occurred. Noise - induced hearing impairment occurs predominantly at higher frequencies (3000−6000 Hz), with the largest effect at 4000 Hz. It is irreversible and increases in severity with continued exposure.

The consequences of NIHL include :a) Social isolationb) Impaired communication with coworkers and familyc) Decreased ability to monitor the work environment

(warning signals, equipment sounds)d) Increased injuries from impaired communication and

isolatione) Anxiety, irritability, decreased self - esteemf) Lost productivityg) Expenses for workers’ compensation and hearing aids.For a detailed account on noise pollution and control kindly refer to chapter on environmental pollution.

VibrationIncreased mechanization and industrialization has introduced a number of tools which produce variable quantities of vibration. In today’s world, vibration induced illness is common in Foundry workers, Shipyard workers including workers in the ship breaking industry, Chain saw operators, Grinders and drivers of various vehicles which vibrate. What has been observed is that the number of affected people increases as the intensity and duration of vibration exposure increases. This type of exposure - response relationship indicates a possible link between health effects and the total amount of vibration energy entering the hands or body. Depending on the intensity of exposure, the symptoms may appear months or years after the start of the exposure.

Three important factors affect the health effects that can result from exposure to vibration :

The threshold value ● or the amount of vibration exposure that results in no adverse health effects In other words, it is the maximum intensity of vibration to which workers can be exposed every workday for their entire full - time employment without developing numbness, paleness or chill of fingers.The dose - response relationship ● (how the severity of the ill health effects is related to the amount of exposure): What has been observed is that the number of affected people increases as the intensity and duration of vibration exposure increases.Latent period ● (time from first exposure to appearance of symptoms) : The higher the intensity, the shorter the latent period.

Effects of VibrationHand - Arm Vibration Syndrome (HAVS) & Vibration - induced white finger (VWF) : It is the most common condition among the operators of hand - held vibrating tools. Vibration can cause changes in tendons, muscles, bones and joints, and can affect the nervous system. Collectively, these effects are known as Hand - Arm Vibration Syndrome (HAVS). The symptoms of VWF are aggravated when the hands are exposed to cold.

Hand-arm vibration syndrome is also known as Raynaud’s phenomenon of occupational origin. Vibration is just one cause of Raynaud’s phenomenon. Other causes are connective tissue diseases, tissue injury, diseases of the blood vessels in the fingers, exposure to vinyl chloride, and the use of certain drugs. The resulting reduced blood flow can produce white fingers in cold environments.

Workers affected by HAVS commonly report :Attacks of whitening (blanching) of one or more fingers ●when exposed to coldTingling and loss of sensation in the fingers ●Loss of light touch ●Pain and cold sensations between periodic white finger ●attacksLoss of grip strength ●Bone cysts in fingers and wrists ●

The development of HAVS is gradual and increases in severity over time. It may take a few months to several years for the symptoms of HAVS to become noticeable. Hand - arm vibration exposure affects the blood flow (vascular effect) and causes loss of touch sensation (neurological effect) in fingers.

The severity of hand - arm vibration syndrome depends on several other factors, such as Protective practices and equipment including gloves, boots, work - rest periods, duration of exposure each workday, Years of employment involving vibration exposure, State of tool maintenance, acceleration of vibration, frequency of vibration, the characteristics of vibration exposure, work practice, personal history and habits.

Whole - Body Vibration : Whole - body vibration can cause fatigue, insomnia, headache and “shakiness” shortly after or during exposure. The symptoms are similar to those that many people experience after a long car or boat trip. After daily exposure over a number of years, whole - body vibration can affect the entire body and result in a number of health disorders. Sea, air or land vehicles cause motion sickness when the vibration exposure occurs in the 0.1 to 0.6 Hz frequency range. Studies of bus and truck drivers found that occupational exposure to whole - body vibration could have contributed to a number of circulatory, bowel, respiratory, muscular and back disorders. The combined effects of body posture, postural fatigue, dietary habits and whole - body vibration are the possible causes for these disorders.

Studies show that whole - body vibration can increase heart rate, oxygen uptake and respiratory rate, and can produce changes in blood and urine. Researchers have noted that exposure to whole - body vibration can produce an overall ill feeling which they call “vibration sickness.” Many studies have reported decreased performance in workers exposed to whole

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- body vibration. As in all occupational exposures, individual sensitivity to vibration varies from person to person.

Vibration and Noise : Since most vibrating machines and tools produce noise, a vibration - exposed worker is likely to be exposed to noise at the same time. Studies of hearing loss among lumberjacks revealed that, for equal noise exposure, those with Vibration-induced White Finger (VWF) had greater hearing loss than those without VWF. The reason for this effect is not clear. Studies of the effect of separate and simultaneous exposure to noise and whole - body vibration have concluded that whole - body vibration alone does not cause hearing loss. However, simultaneous exposure to noise and vibration produces greater temporary hearing loss than noise alone.

Prevention & Control of hazards Due to Physical EnvironmentPersonal Protective EquipmentThe main danger for employees working in hazardous industries lie in working with chemicals, machinery and tools, noise and vibrations. Therefore, health and safety measurements focus on chemical handling, dust formation, safety of machines and tools and noise and vibrations. An employer must meet specific requirements concerning “personal protective equipment” (PPE), such as gloves, goggles, hard hats, face shields and ear muffs.

Responsibilities of an Employer : It is the responsibility of an employer to :a) Survey the workplace to identify hazards, (this survey

must be in writing and must be available to workers or their representatives upon request),

b) Determine whether any hazard requires PPE,c) Pay special attention to working conditions or processes

that can produce the following hazards :- Falling objects- Objects that could puncture the skin- Objects that could roll over workers’ feet- Toxic chemicals- Heat- Harmful dust- Radiation

In order to avoid accidents and unhealthy environments, managers give high priority to :

Reducing the frequency of accidents by good plant design ●and good operational control; Good - housekeeping measures are general measures within the company organising issues as occupational health and safety and also environment. These measures often are not very complex, but rather basic and therefore important. Good - housekeeping is about reducing and preventing accidents and injuries by organising the company, especially the work floor. Measures will vary from training employees on possible hazards associated with the materials they work with, handling machines, using adequate protective gear, reducing spillages by putting down working procedures to keeping the work floor clean and tidy.Minimising the consequences if they occur by appropriate ●

plant design and procedures, but in addition a predetermined set of emergency plans for personnel.Be aware of the possible origin of accidents. ●

Reassess hazards whenever necessary, especially when new equipment is installed or following accidents. The employer must ensure that all PPE used is the right kind of equipment for the job, and that it is maintained properly, even when workers are using their own equipment. Every employer must ensure that :a) PPE provides a level of protection above the minimum

required to protect the worker,b) All PPE fits properly,c) No defective or damaged PPE is used,d) All PPE is properly cleaned and maintained on a regular

basis.Employers must train all workers who use personal protective equipment. Training must cover : when and which PPE is necessary, how to know if it fits properly, how to put on, remove, adjust and wear PPE, how to dispose of PPE and the limitations of using PPE. Training must be given whenever working conditions change, or when new or different PPE is used, or if a worker does not understand or remember any topic in the training. Employers must certify in writing that each worker has received and has understood the training. Workers should know how to inspect all PPE to make sure that it is not damaged. Defective PPE should be replaced as soon as the defect occurs.

It is always preferable for the employer to remove or minimize hazards. The provision of PPEs does not enable an individual to take liberties against the hazard, as it is not foolproof. Hence, emphasis should be directed at prevention of hazards by making the system foolproof. Wearing PPE can be uncomfortable (especially in hot weather) or awkward, and many people complain that it gets in the way of doing the job. Although PPE cannot usually completely protect the wearer, people often get a false sense of security when they use it. Also, PPE protects only the person wearing it and many people may not be able to wear PPE due to certain types of medical conditions. Problems such as incorrect fit, use of the wrong PPE for the job, use of damaged or poorly maintained PPE or inconsistent PPE use can all result in less than adequate protection.

The material and shape of special protective overalls should vary with the substances involved e.g. liquid proof or gas proof against corrosive and irritant liquids / gases; asbestos suits complete with a helmet, gloves and boots against risks of excessive heat and fire; against radio - active substances, washable material so designed as to cover other clothing at the neck and wrists. Washing of working clothing is necessary at least once a week as prevention against contamination of other clothing.Types of Personal Protective Equipment

Eye and face protection : Goggles and face protection must be used when workers are at risk from flying particles, liquid chemicals, acids or caustic liquids, chemical gases or vapours. Workers must also be protected from radiation during welding, torching, soldering, and brazing, or other operations that emit light. Goggles and face protection must meet certain design

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criteria for safety. Workers with errors of refraction should have the error corrected. Glasses or transparent plastic materials for goggles and windows of protectors should be free from striae and air bubbles. All goggles intended for mechanical protection should be splinter proof. Goggles and shields for workers engaged in welding, furnace work or any other operation where their eyes are exposed to glare should have filter lenses or windows of standard absorption value against ultraviolet and heat rays. Nonflammable, transparent visors, free of scratches should be provided for protection against glare and sparks. Goggles, when not in use should be kept in special closed containers protecting them from mechanical damage and should be inspected at regular intervals once a month and all defective parts should be replaced immediately.

Head protection : Hard hats/Helmets must be worn where there is a danger of falling objects. Specialized hard hats are required to reduce electrical shock hazards. Well fitting helmets made of aluminium; fibreglass or steel should be worn as a protection against falling or flying objects and blow on the head. For protection of hair from overhead moving belt, well fitting caps of washable and non - inflammable material should be used.

Foot protection : Safety shoes with impact protection are required in work areas where heavy objects or tools could be accidentally dropped on the feet. Safety shoes with compression protection must be worn where objects could roll over workers’ feet, and in operations involving skid trucks, hand trucks, dollies, etc. Safety shoes with puncture protection are required when working around nails, wire, tacks, scrap metal, and other objects that could pierce the feet. Leggings for workers handling molten metals should be made of asbestos or other suitable heat resisting material, extending to the knee. At the lower end they should also cover eyelets of footwear. Metal toe guards or safety boots or shoes should be worn in operations where heavy objects are handled. Footwear for workers handling corrosive liquids should be of rubber, specially treated leather, wood or other suitable corrosion resisting material. Footwear for electrical workers should have nonconductive soles.

Hand Protection : Gloves are required to protect workers from cuts, scrapes, punctures, burns, chemical absorption, or temperature extremes. It is crucial that the type of glove being used is the right one for the job since incorrect gloves may provide no protection. This is a particular problem with chemical absorption where incorrect gloves may allow certain chemicals to reach the skin. Gloves for workers handling sharp edged or abrasive objects should be made of tough material and where necessary provided with special reinforcements of leather pieces or even a metal piece over the palm. Gloves should also be made of steel mesh for use in cutting process. Gloves and sleeves for workers handling hot metals could be made of asbestos or other heat - resisting material. Gloves with sleeves made of rubber capable of withstanding voltage of 10000 or more should be used for electrical workers. Gauntlets made of natural synthetic rubber or pliable plastic material should be used when handling corrosive liquids. Close fitting gloves should be used for avoiding exposure to toxic fumes and infectious agents. Barrier creams prevents penetration of irritant substance into the skin. Ideally a barrier cream should be non - irritating, nonsensitising, insoluble in substance

against which being used, easily removable and cosmetically agreeable.

Hearing Protection : Appropriate ear muffs or ear plugs must be made available as a last resort if it is not possible to make the workplace less noisy. Employers must ensure that workers are exposed to less than 90 decibels of noise over an 8 - hour day. If noise levels reach 85 decibels over an 8 - hour day, the employer must develop a hearing conservation program. If no other method of eliminating or reducing the noise exposure is found, the employer must supply PPE. These reduce the sound level exposure by about 20 dB each.

Respirators : Appropriate respirators must be worn as a last resort, if it is not possible to ventilate the work area properly. The following are a few types of respirators used in various industrial processes and environments. These should all be inspected and tested at regular intervals by responsible trained persons.

A mechanical filter respirator can only filter the suspended atmospheric impurities. A wide variety of impressive patterns and designs are available. None afford protection against solvent vapours, injurious gases or in atmospheres deficient in oxygen, and are essentially dust and fume filters in an otherwise healthy atmosphere. The simplest example of such type of respirator is the common surgical gauze mask. By introducing a thin layer of wet cotton wool in between the layers of gauze, it may be worn as a protection against coarse particles, such as fibres or sawdust. Their efficiency against fine particulate, such as those of silica dust, will depend upon the quality of the filtering medium. In course of time, these filters become clogged and there is increased resistance to breathing. The filters should then be washed or changed. Everybody should be supplied with a personal mask.

Chemical cartridge respirators and canister masks ensure the purification of air, which passes through the canisters containing specific neutralisers against specific toxic gases. The canisters have a particular coloured design painted on them indicating the specific toxic gases against which they afford protection; e.g. an orange coloured canister indicates that it is meant to be used against nitrous fumes. The user has to depend upon the oxygen content of the atmosphere, therefore, such respirators should not be worn in confined or poorly ventilated places or where the concentration of the offending gases is high.

The term ‘supplied - air - respirators’ means a respirator equipped with a hose line, through which fresh air is supplied under positive pressure whereas through hose masks the wearer can inhale air at atmospheric pressure. These are also used when the canister for cartridge respirator cannot be used due to high concentration of dangerous gases or fumes.

A self-generated oxygen mask is an oxygen breathing apparatus consists of a face piece with a corrugated tube connecting it to an oxygen tank or cylinder. This is used by workers engaged in fire fighting, rescue or repair work in atmospheres containing high concentrations of gases or which is deficient in oxygen or sufficient pure air supply. A self - generated oxygen mask is a new type of oxygen breathing apparatus fitted with a small canister containing a chemical. Moisture from the inhaled air starts a chemical reaction, which liberates oxygen.

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Safe Work EnvironmentDesign of Building : All buildings, permanent or temporary should be structurally safe and sound to withstand the stress and strain of machinery. Single storey construction is the usual rule as it allows flexibility of layout. Any intensity of natural light can be obtained in it by a combination of wall and roof lighting and it is easier to manage natural ventilation. By careful orientation, direct exposure to the tropical sun can be avoided. Protection from conducted heat can be achieved by a choice of suitable material. Asbestos lining of the walls and ceilings will reduce the noise of machines by controlling the reverberation, resonance and sympathetic vibrations. This will also make the building fireproof.

Space Requirement : A floor area of 3.8 sq.m and 14.2 cu.m of space per worker should be provided. The height of the work rooms should not be less than 3 m. In calculating the space, no deduction need be made for furniture, machines and material, but a height above 4.2 meters should be excluded. The floor should, however, not be crowded with machinery. Individual machines or process units should have sufficient space around them to permit safe operation.

Lighting : Workrooms should be adequately provided with natural and /or artificial lighting. Any special type of work should have special, extra or sport lighting suitable for the operations. In all places where persons work or pass through, enough diffuse background lighting should be ensured. Natural lighting is ensured by the provision of skylights and windows located and spaced with devices to avoid glare. Artificial lighting should be provided where the daylight illumination is insufficient. It should be uniform and free from sharp and contrast shadows and direct or reflected glare. Supplementary lighting specifically designed for particular visual task should be so arranged as to avoid glare, flicker or after - image. Emergency lighting should be provided in all important stairway exits and passages, to and from work places and windowless buildings. The fluorescent tube in strip lighting is being increasingly used. Their efficiency is high and running costs are low. They give uniform illumination and there is low heat formation with absence of shadows. However, in course of time when the tube gets exhausted it develops a flicker, which is irksome to the eyes and also produces a stroboscopic effect.

Ventilation : Modern concept of ventilation requires replacement of vitiated air by supply of fresh outdoor air, the quality of the incoming air should be such that its temperature, humidity and purity are conducive for healthful working. Clean fresh air should be supplied to enclosed work places and it is recommended that in work rooms and assemblies there should be 4 to 6 air changes in one hour. If the air is changed more frequently, i.e. more than 6 times in one hour, it is likely to produce a draught which should be avoided. Where an adequate supply of fresh air cannot be obtained by natural ventilation, mechanical ventilation should be provided. All dust, fumes, gases, vapours or mists generated and released in industrial processes should be removed by local exhaust ventilation at their point of origin.

Thermal Comfort : Temperature and humidity should be maintained in enclosed work places suitable to the kind or

work performed. In localities subject to high or low seasonal temperatures appropriate means such as heat insulation of roofs, walls and floors, and even of doors and windows should be adopted. All employees should be protected against radiant heat and excessive temperature from heated machines or hot processes by heat insulation of the equipment and / or by suitable protective clothing. In industries involving exposure of workers to high or low temperatures, ‘transition rooms’ should be provided so that the workers can gradually adjust themselves to the external climatic environments. Roof - shelters and windbreakers should be provided for yard - workers where necessary.

Working Comfort : Seats and Workbenches of suitable shape and height should be provided for workers. The seats should be so placed that working material can be reached easily without strain or having to bend forward unduly. Seats should also be provided for all workers who have to work in a standing position, for rest during occasional short interruptions in their work.

Sanitary Conveniences : These should be conveniently located.

(a) Latrines : Scales of latrine accommodation is 4 for the first 100 workers and 2 for subsequent 100 workers or part thereof.

(b) Urinals : Two urinals for every 100 workers upto 500 and there after one for 100 workers are to be provided. For female workers separates sanitary conveniences are to be provided.

(c) Wash Basins : Adequate hand washing facilities should be provided for persons whose work involves contact with any injurious substances, there should be at least one tap for every 15 workers.

(d) Bath - rooms : Adequate number of bathrooms for bathing and washing of clothes should be provided.

(e) Spittoons : Sufficient number of spittoons should be placed at convenient places.

(f) Cloak Rooms : Well - ventilated rooms with individual lockers should be provided for dressing purposes and storage of personal clothing.

Drinking Water : An adequate supply of cool and safe drinking water should be provided in a readily accessible place. Water coolers are ideal and most hygienic. Proper precautions to prevent contamination of water in tanks, pails and other containers must be enforced, section 18 of the factories Act lays down that every factory having more than 250 workers will provide cool drinking water during hot weather.

House-Keeping : It implies general cleanliness and orderliness of the plants, the tools and the products. Cleaning and sweeping should be done during non - working hours; vacuum cleaning or wet mopping should be adopted. Effective drainage should be maintained where wet processing is carried out. False floors, platforms, mats or other dry standing places along with suitable footwear should be provided in oily and greasy places. However, ‘house - keeping’ means much more than merely keeping the working places clean. “There is a place for everything and everything in its right place” is a tried and true axiom of industrial safety. Stumbling and tripping

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due to improper house - keeping is another potential cause of accidents.Miscellaneous Requirements

Infestation with rodents, insects and vermin should be eliminated by suitable measures. Workrooms and work places should not be used as living or sleeping quarters. No food, drink, betel nut or leaves or tobacco should be consumed or

brought by any worker into any workroom in which dangerous and obnoxious materials, particularly lead and radioactive substances, are in use. Any one suffering from communicable diseases should be at once isolated and preventive and control measures instituted.

231 Social Security and Labour Laws

Ashok K. Jindal, Puja Dudeja

Rapid industrialisation of the country has led to a sharp increase in the Labour force in the twentieth century. The expansion of the workforce has taken place more in the unorganised sector. Today a staggering 92.5% of the Indian Labour is employed in this sector. It comprises largely the needy small and marginal farmers, the contract labourers and the agricultural workers. The organised sector, considered better off, employs 280 lacs employees. Out of these, 195 lacs are in the public sector and 85 lacs in private sector.

The earliest legislation in the field of Social Security in India was the “Fatal Accident Act” of 1855 that provided compensation to workers who died as a result of an industrial accident. However, the law remained merely on paper, as it was left to the heirs of the deceased to prove that the accident occurred due to the personal negligence of the factory owner, which was a Herculean task. The powerful Indian Bourgeoisie had thus ensured by getting this clause inserted, that Social Security for the working class remained a non starter. The easy availability of cheap labour and the capital might of the Indian industrialist ensured that it took a long time for the Indian labour force to get organized and fight for their rights. History has shown that legislation and Social Security in industry has come about not due to growth in knowledge or due to a philanthropic attitude of the employers or Government but due to a continuous struggle by the working class. The constant pressure from the workers, trade unions and the ILO forced the Indian Government to enact legislations in the realm of Social Security and Labour Welfare. These were the Workmen’s Compensation Act 1923, the ESI Act 1948 and the Factories Act 1948. While the first two dealt with primarily compensation of occupational diseases and injuries, the Factories Act provided for enforcing Safety and Health measures on the factory floor.

The Workmen’s Compensation Act 1923 was based on the principle of employer’s liability to compensate the worker. This legislation provided for compensation of a personal injury from an industrial accident or an occupational disease and also led

to the setting up of special machinery to deal with claims of compensation under the Act. The Workmen’s’ Compensation Act became an important means in the system of social security for labour in India till independence. It provided for compensation in case of death, total disability, permanent partial disability and temporary disability. However, this Act was criticized as being inadequate to provide compensation to workers in case of Employment Injury or Occupational Disease as the worker had to undergo protracted litigation against the employer to get his legitimate dues. In the name of collective responsibility and functioning of the state, the employer and the employee; and with the assistance of liberal intellectuals and administrators, a compulsory contributory Health Insurance Scheme for Industrial workers was framed giving birth to the ESI Act 1948, which replaced the Workmen’s Compensation Act in respect of employees covered by the former.

Under the Constitution of India, Labour is a subject in the Concurrent List where both the Central & State Governments are competent to enact legislation subject to certain matters being reserved for the Centre. Table - 1 gives the responsibilities under union and concurrent list.

Table -1:Responsibilities under union and concurrent list

Union List Concurrent List

Regulation of labour & safety in mines and oil fields

Trade Unions; industrial and labour disputes

Industrial disputes concer-ning Union employees

Social Security and insurance, employment and unemployment

Union agencies & institutions for “Vocational training”

Welfare of labour including conditions of work, provident funds, employers ‘invalidity and old age pension and maternity benefit

List of Acts Related to LabourThe Child Labour (Prohibition and Regulation) Act 1986 ●The E.P.F. and Miscellaneous Provisions Act, 1952 ●Industrial Disputes Act, 1947 ●The Maternity Benefit Act, 1961 ●

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Minimum Wages Act, 1948 ●Payment of Bonus Act, 1965 ●Payment of Gratuity Act, 1972 ●Payment of Wages Act, 1936 ●Payment of wages (Amendment) Act 2005 ●Public Provident Fund Act, 1968 ●Workmen’s Compensation Act, 1923 ●Factories Act, 1948 ●ESI Act , 1948 (Employees State Insurance Act, 1948) ●

The Child Labour Act 1986The problem of child labour is a big challenge before the nation. Government has been taking various pro - active measures to tackle this issue (33). This quandry will require concerted efforts from all sections of the society. This problem is intimately related to poverty. Based on the recommendations of Gurupadaswamy Committee, the Child Labour (Prohibition & Regulation) Act was enacted in 1986. The Act prohibits employment of children in certain specified hazardous occupations and processes and regulates the working conditions in others. The list of hazardous occupations and processes is progressively being expanded on the recommendation of Child Labour Technical Advisory Committee constituted under the Act. National Policy on Child Labour was formulated in 1987. The Policy seeks to adopt a gradual & sequential approach with a focus on rehabilitation of children working in hazardous occupations & processes in the first instance. The Action Plan in the Policy for tackling this problem is as follows :

Legislative Action Plan for strict enforcement of ● Child Labour Act and other labour laws to ensure that children are not employed in hazardous employments, and that the working conditions of children working in non - hazardous areas are regulated in accordance with the provisions of the Child Labour Act. Focusing of General Developmental Programmes for ●Benefiting Child Labour.Project Based Plan of Action envisages starting of projects ●in areas of high concentration of child labour. Pursuant to this, in 1988, the National Child Labour Project (NCLP) Scheme was launched in 9 districts of high child labour endemicity in the country.

The Factories Act 1948 The factories Act was enacted by the parliament of India in 1948, and since then it has been revised and amended from time to time (34), the latest being the factories (Amendment) Act, 1987. The amendment in 1987 was elaborated following the Bhopal Gas Tragedy. This land mark amendment of 1987, in the factories Act - 1948, in effect means that the affair of the Company cannot be entrusted to a managing agent, and the owners or directors of the factories will be deemed to be the ‘occupier’ of the factory. This makes the factory owners directly responsible for ensuring Safe and Healthy working conditions in their factory.

Scope of the Act : The Act defines “factory” as an establishment employing 10 or more workers where power is used, and 20 or more workers where power is not used. The term ’worker’ includes within its meaning contract labour employed in the manufacturing process. The Act applies to the whole of India except the State of Jammu & Kashmir, under the provisions

of the Act, the State Governments are authorized to appoint besides the Chief Inspector or Factories as many Additional Chief Inspector of Factories, joint Chief Inspectors, Deputy Chief Inspectors and Inspectors as they think fit to enforce the provisions of the law. The system of enforcement of Factories Act, 1948 is established on two tier basis. At the Central level, the Director General Factory Advisory Services & Labour Institutes (DGFASLI) has an advisory role. It coordinates the activities of the factory Inspectorates and provides training and advisory services to the inspectors. In addition it also assists the Ministry in drafting amendments to the Act and the Model Rules. The latter are recommended to the State Governments for adaptation with necessary modifications to suit local conditions. The Factory Inspectorates under the State Government and Union Territories carry out the enforcement functions (35).

General Duties of Employer : The Act specifically directs the employer to ensure the Health, Safety and Welfare of all workers while they are at work in the factory. His duties include ensuring Proper maintenance of plant and systems of work in the factory; Ensuring safety in connection with the use, handling, storage and transport of articles and substances; Provision of information, instruction, training and supervision necessary to ensure the health and safety of all workers at work; Provision and maintenance of risk free and safe means of access, and egress from, all places in the factory; and, Provision, maintenance and monitoring of working environment in the factory so that the same is risk free and safe.

The Inspecting Staff : The state government is empowered to appoint inspectors/Additional Chief Inspector of Factories and as many officers, it thinks fit to ensure that provisions of the Act are complied with (36), these inspectors are empowered to enter any factory or any place which he believes is being used as a factory and undertake inspections.

Certifying Surgeons : The State Government is empowered to appoint qualified medical practitioner to be certifying surgeons for the purposes of the Factories Act.

Health and Safety : Elaborate provisions have been made in the Act under chapter III, IV and IV A, with regard to health and safety or workers, These chapters deal with laws pertaining to such matters as cleanliness, lighting, ventilation. treatment of workers, effluents and their disposal, elimination of dusts and fumes in the workplace, provision of spittoons, control of temperature, supply of cool drinking water and for the employment of cleaner to keep the water closets clean. A minimum of 350 cu feet of space for each worker for factories installed before 1948 and 500 cu feet for factories installed after 1948 has been prescribed by the govt not taking into account space more than 14 feet above ground level. The Act also prescribes in detail provisions relating to the safety of workers. Section 40B provides for the appointment of “Safety Officers” in every factory wherein 1000 or more workers are ordinarily employed. The state Government is empowered to prescribe maximum weights, which may be lifted or carried by men, women and children. Some of the other safety provisions relate to caring of machinery, devices for cutting off power, hoists and lifts, protection of eyes and precautions against dangerous fumes, explosives and inflammable materials.

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Welfare : Chapter V of the Act relates to welfare measure for the worker. The Act specified that wherein more than 250 workers are ordinarily employed, a canteen shall be provided. In every factory, wherein 30 or more women workers are ordinarily employed, a crèche should be provided. Provisions have been made under the Act to ensure adequate washing facilities, appliances, shelters, rest rooms and lunchrooms. There should be a welfare officer for every factory employing more than 500 workers.

Employment in Hazardous Processes : Chapter IV A, incorporate by the Factories (Amendment) Act, 1987, relates to hazardous processes. A site appraisal Committee is to be constituted to submit recommendations on the siting of factories using hazardous processes. Provisions have been made for workers, participation in safety management in industries involving hazardous processes.

Hours of Work : The Act has prescribed a maximum of 56 hrs of work (60 hrs including overtime) per week with maximum spread over of work upto 12 hrs per day (including rest interval of ½ hr after every 5 hrs of work). For adolescents, the maximum hours of work per day have been restricted 4 ½ hours.

Employment of Young Persons and Women : The Act prohibits employment of children below 14 years of age. Persons between the ages of 15 and 18 years are to be duly certified as adolescents by “Certifying Surgeons” and also deemed thus fit to work. Adolescent employees and Women are restricted from employment in certain dangerous occupations and hazardous processes and are allowed to work between 6 A.M and 7 P.M.

Leave with Wages : The Act lays down that besides weekly holidays, every worker will be entitled to leave with wages after 12 months of continuous work at the rate of one day for every 20 days of work for adults and one day for every 15 days of work for adolescents.

Notifiable Occupational Diseases : The Act gives a schedule of Notifiable disease (see 3rd schedule of the Act). It is obligatory on the part of the factory management to give information regarding specified accidents, which cause death or serious bodily injury and regarding occupational diseases. Provisions have also been made for safety and occupational health surveys in the factories.

Social Security SchemesSocial Security is a wide term and it is difficult to have a standard uniform definition of the term. The international Labour organization (ILO) defines it as “the Security that society furnishes through appropriate organization against certain risk to which its members are exposed. It is social because it represents a collective effort by society. The security is provided in an organized form and therefore is not haphazard. Examples of Social security schemes in India are :1. Employees Provident Fund Organization2. Central Government Health Scheme (CGHS)3. Central Maternity Benefit Act 19614. Workmen’s Compensation Act 19235. Employees State insurance Act 19486. The Family Pension Scheme 19717. Various insurance Schemes of LIC, private insurers

The Employees State Insurance Act 1948The ESI scheme is hailed as the largest Social Security Scheme of its kind in Asia. The ESI Act 1948 was enacted to “provide for certain benefits to employees in case of sickness and employment injury and to make provision for certain other matters in relation thereto. It has undergone amendments several times. The ESI Act, at present, applies in the first instance to non - seasonal factories using power in the manufacturing process and employing 10 or more persons and non power using factories employing 20 or more persons for wages. A factory or an establishment to which this Act applies shall continue to be governed by this Act, notwithstanding that the number of persons employed there at any time falls below the limit specified by or under this Act or the manufacturing process therein ceases to be carried on with the aid of power.

The Act contains an enabling provision under which the ‘appropriate government’ is empowered to extend the provisions of the Act to other classes of establishment. Under these provisions most of the state governments have extended provisions of the Act to certain additional establishments, viz., Shops, hotels, restaurants, cinemas including preview theatres, road motor transport agencies, newspaper establishments, employing 20 or more persons; Beedi manufacturing establishments employing 10 or more persons in the implemented area; and, State pencil manufacturing establishments employing one or more persons (37).

All factories or establishment to which the Act applies are required to register themselves in the Local office of the ESI Corporation. The Act empowers the Central Government, the State Government and the Corporation to frame rules for the running of the scheme. For carrying out its functions a statutory body called the ESI Corporation has been set up with the Minister of Labour as its Chairman, It has representatives of the Central and State Governments, Employers, employees, medical professionals and members of Parliament. The Chief Executive of the Corporation is the director General ESI who is assisted by an insurance Commissioner, a Medical Commissioner, a Finance Commissioner and an Actuary. The DGESI and the Finance Commissioner are appointed by the Central government. The other executives get promoted through ESI departmental channels. The Corporation has one Regional office each, in all the States who have local offices under them in all areas covered by the Act. There is a Medical Benefit Council, which decides medical care polices, headed by the DGHS who is assisted by the Medical Commissioner. The other members of the Medical Benefit Council include Dy DGHS, State ESI medical heads, and representatives of employers, employees and medical professionals. The latter are nominated by the Indian Medical Association.

The medical care component called the Kingpin of the scheme is to provide full preventive, curative and occupational health services to its beneficiaries (38, 39, 40). Through it the Scheme provides Out - patient treatment, Domiciliary treatment, Specialist Consultation, In - patient treatment, Free supply of drugs, dressing, artificial limbs, aids and appliances, X - ray and laboratory investigations, Vaccination and preventive inoculations, Antenatal care, confinement and postnatal care, Ambulance service or conveyance charges for

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going to hospitals, diagnostic centres, etc. where admissible, Family welfare services and other national health programme services, Medical certification, Special provisions including super - specialist services, and, early detection and diagnosis of occupational diseases.

Initially the medical care was provided only to workers in active employment. It has subsequently been extended to families of workers. In 1989, the Act was amended to include provision of medical care to an IP who ceases to be in insurable employment on account of permanent disablement, subject to payment of contribution, till the date on which he would have been superannuated had he not sustained such permanent disablement. It also brought under the ‘medical care umbrella’ retired workers and their spouses subject to payment of nominal contribution of Rs 10 only by a subsequent amendment. This Scheme is run by the State Governments under the guidance of the Corporation except in Delhi and NOIDA where it is run directly by the Corporation. The State Government bears 1/8th of the cost of medical care and the balance is met by the Corporation. For budgetary calculations the ceiling for the total cost on medical care benefit has been fixed at Rs 500 per IP annually. These benefits are provided free of cost including hospitalization in case of sickness, employment injury and maternity related causes. Medical care is provided either directly through the exclusive ESI hospitals and Dispensaries or indirectly through a panel of private medical practitioners (Panel System). All industrial Centres having large concentration of insured persons have the direct pattern of medical care, and the indirect pattern if restricted to areas having less concentration of insured persons where providing exclusive ESI services is not considered cost effective. It has its own referral chain and patients requiring super specialty treatment can be referred to the zone level ESI hospitals cum occupational Centres. In addition patients can be sent to specialized non ESI hospitals also at the expense of the ESI Corporation. Besides, the ESI Scheme provides the following major benefits :

Sickness Benefit : This consists of periodical cash payment to an insured person if his sickness is duly certified by an ESI/insurance Medical Practitioner. The benefit is payable for a variable period of time depending on the type of illness and subject to the individual remaining under medical treatment provided under the Act. The insured person is protected from dismissal or discharge from service by the employer during the period of sickness.

Maternity Benefit : The benefit is payable in cash for an insured Woman for confinement/miscarriage or sickness arising out of pregnancy/confinement or premature birth of child or miscarriage. For confinement the duration of benefit is 12 weeks, for miscarriage 6 weeks and for sickness arising out of confinement 30 days. The benefit is allowed at about full wages.

Disablement Benefit : The Act provides for periodic cash payment, besides free medical treatment, in the event of a temporary or permanent disablement as a result of employment injury as well as occupational disease.

Dependent Benefit : In case of death, as a result of employment injury, the dependents of an insured person are eligible for periodical payments.

Funeral Benefit : Funeral expenses are in the nature of lump sum payment up to a maximum of Rs 1500 made to defray the expenditure on the funeral of a deceased insured person. This payment is to be made to the eldest surviving member of the family of the deceased.

Unemployment Allowance : This benefit has been introduced from 10 Apr 2005 & provides for an unemployment allowance to an individual for a maximum period of 6 months on account of closure of factory or establishment, retrenchment or permanent invalidity arising out of non employment injury, after being in insurable employment for five or more years.

232 Medical Evaluation of Workers

Leo S Vaz

Keeping in view the problems likely to be encountered by workers in various industries it is essential that the Occupational health physician put in place a detailed surveillance system which would be effective and provide predictive guidelines for prevention of diseases due to occupation. These evaluations explore the physical demands and environmental hazards of a worker’s position. The Occupational Medical Services health care provider reviews the individual’s personal medical and

immunization history to determine whether the worker can assume/continue the duties. The staff provides work - related health and safety advice, administers appropriate vaccines, and enrolls the individual in applicable surveillance programs.

Preassignment (Pre-placement)Some companies require pre - placement testing as a means to determine if the applicant has the capacities to accomplish the specific duties of the job, based upon the physical, environmental and psychological demands of the position. Pre - placement medical evaluations are recommended for individuals whose work involves:

Hazardous industries ●Strenuous activity ●

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Animal contact ●Patient contact, ●Possible exposure to human body fluids ●Potential contact with human pathogens, or ●Work in an area that is used for clinical care. ●

As per factories Act, all workers should undergo a medical examination before entering industrial employment for the first time (engagement or preplacement examination) or within I5 days of employment. The focus of these exams is to avoid potential work - related accidents by detecting medical conditions early. Diagnosis made on these medical examinations should be strictly confidential. Persons suffering from unsafe traits, such as, ‘accident - proneness’ should not be employed near hazardous jobs.

Periodic Medical SurveillanceMedical surveillance is a valuable tool for assuring and maintaining a healthful workplace environment. Medical surveillance is the periodic testing of employees exposed to potentially hazardous materials or other risks in the workplace. The purpose of medical surveillance is to detect early signs of work - related illness so that appropriate action can be taken to eliminate the underlying exposures. The Factories Act requires companies to conduct Periodical medical examination at regular intervals (monthly, quarterly, yearly) depending upon the hazard to which a worker is exposed. For instance, medical surveillance is required to detect illnesses caused by materials such as asbestos, lead, formaldehyde, benzene, and hazardous waste. The clinical examination should be supplemented by special investigations where indicated. Date and results of such examination should be recorded in special registers maintained for this purpose.

Post - Illness or Injury (return - to - work) An employee’s health status may be reevaluated following prolonged absence from work due to illness or injury. This exam is conducted to ensure that an employee has sufficiently recovered from an illness or injury to perform the job without harm to himself/herself or to others. In addition medical examination of workers should be carried out on their returning from sick leave and those seeking change of employment.

Pre Retirement / Change of Job An employee’s status requires to be evaluated prior to his retirement or change of job so that it can be assessed as to whether he has suffered from disability/ disease due to the job. This is also beneficial to the employer as the employee cannot make subsequent claims.

Components of TestsPhysical testing is composed of several distinct tests. Exam components may vary based upon the protocols required by

your company. In general, an occupational health test may include:

Physical exam ●Vision ●Audiometry Tests ●Pulmonary Function (PFT) ●ECG ●Blood tests ●Chest X - ray ●

(a) Physical Exam : The physical exam is conducted by an occupational health physician, and is designed to provide an assessment of health as it relates to the specific occupation. The evaluation usually consists of a thorough physical exam: review of systems (head/neck, heart/lungs, gastrointestinal, genitourinary, skin and soft tissue, musculoskeletal, neurological). A physician will usually inquire further on any positive responses in the medical history questionnaire to help determine physical ability to work.

(b) Vision Screening : This test screens for visual acuity (both near and far visual fields, depth perception) or colour (if required on job). A glaucoma screen may also be performed under certain circumstances.

(c) Audiometric Tests : This testing is part designed to protect workers with significant occupational noise exposure from suffering material hearing impairment.

(d) Pulmonary Function Test : Pulmonary function testing (PFT), or lung function testing, is carried out in workers working in industries which are likely to have adverse affects in pulmonary function.(e) ECG

(f) Blood Tests : as considered essential by the physician.

(g) Chest X-Ray : A chest X-ray is usually done for the evaluation of lungs, heart and surrounding anatomy.

ReportThe physician must send his report to the third party/employer who requested the assessment. He may discharge the mandate entrusted to him by giving his opinion in the report. This opinion may take any of the following forms:

Unconditional acceptance of the applicant; ●Acceptance despite the presence of limitations not entirely ●incompatible with the job, accompanied by a description of these limitations;Acceptance conditional upon accommodations made to the ●job because of incompatible limitations;Refusal because of impairments resulting in total ●incompatibility.

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233National Programme for Control and Treatment of Occupational Diseases

Leo S Vaz, Ashok K. Jindal & Puja Dudeja

Burden of Occupational Disease and InjuriesThere are 100 million occupational injuries causing 0.1 million deaths in the world according to WHO. It is also estimated that in India, 17 million occupational non-fatal injuries (17% of the world) and 45,000 fatal injuries (45% of the total deaths due to occupational injuries in the world) occur each year. Out of 11 million cases of occupational diseases in the world 1.9 million cases (17%) are contributed by India and out of 0.7 million deaths in the world 0.12 (17%) is contributed by India. National Institute of Occupational Safety & Health (NIOSH) has developed a priority list of 10 leading work-related illnesses and injuries. Three criteria were used to develop the list: (a) The frequency of occurrence of the illness or injury (b) Its severity in individual cases and (c) Its potential for prevention. Occupational lung disease is first on the list. Silicosis, asbestosis and byssinosis are still prevalent in many parts of the world. The prevalence of Occupational Asthma varies from 10% to nearly all of the workers in certain high-risk occupations. NISOH considers occupational cancer to be the second leading work-related disease, followed by cardio-vascular diseases; disorder of reproduction, neurotoxicity, noise induced hearing loss, dermatological conditions, and psychological disorders.

Global Strategy for Occupational HealthThe first WHO programme on occupational health was designed in 1950, just two years after the Organization was established. WHO joined with ILO to form the Joint ILO/ WHO Committee on Industrial Hygiene. In the 1960s and most of the 1970s, the WHO occupational health strategy focused on the scientific and technical aspects of occupational health services, including the early diagnosis of occupational diseases, and training and education in occupational health. A new strategy for the further development of occupational health services was adopted in 1979, with the World Health Assembly Resolution WHA32.14 on the proposed comprehensive workers’ health programme, stressing the need to organize primary health care services “as close as possible to where people live and work”. To mitigate the adverse health impact of work-related risk factors, the WHO Programme on Occupational Health set up a new agenda in the 1990s with the adoption of a new resolution in 1996 (WHA 49.12) which led to the development of the WHO Global Strategy for Occupational Health for All.

The global strategy for achieving occupational health for all (WHO-SEARO 1999) includes the following ten major areas for action (41):1. Strengthening of international and national policies for

health at work and developing the necessary policy tools.2. Development of healthy work environment.3. Development of healthy work practices and promotion of

health at work.4. Strengthening of occupational health services (OHS).5. Establishment of support services for occupational health.6. Development of occupational health standards based on

scientific risk assessment.7. Development of human resources for occupational health.8. Establishment of registration and data systems,

development of information services for experts, effective transmission of data and raising of public awareness through public information.

9. Strengthening of research.10. Development of collaboration in occupational health and

with other activities and services.

National ProgrammeOccupational health was one of the components of the National Health Policy 1983 and now also included in National Health Policy 2002, but very little attention has been paid to mitigate the effect of occupational disease through proper programme. Ministry of Health & Family Welfare, Govt. of India has launched a scheme entitled “National Programme for Control & Treatment of Occupational Diseases” in 1998-99. The National Institute of Occupational Health, Ahmedabad (ICMR) has been identified as the nodal agency for the same (42).

Following research projects has been proposed to be initiated by the Government :1. Prevention, control and treatment of silicosis and silico-

tuberculosis in Agate Industry.2. Occupational health problems of tobacco harvesters and

their prevention.3. Hazardous process and chemicals, database generation,

documentation, and information dissemination.4. Capacity building to promote research, education, training

at National Institute of Occupational Disease.5. Health Risk Assessment and development of intervention

programme in cottage industries with high risk of silicosis.

6. Prevention and control of Occupational Health Hazards among salt workers in the remote desert areas of Gujarat and Western Rajasthan.

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Study Exercises (For Section 11)MCQs1. Father of occupational medicine is (a) Bernardino Ramazzini

(b) Karl Marx (c) Donald Hunter (d) John Simon2. First Industrial Health nurse (a) Philippa Howerday

(b) Mother Terasa (c) None of the above3. Which of the following is not an agicultural hazard

(a) Musculoskeletal disorders (b) Bagassosis (c) Byssinosis (d) Silicosis

4. Which is not true of occupational cancer (a) History of exposure to carcinogen is present (b) Danger of getting cancer even after exposure has ceased (c) Location and histological pattern are quite common in most occupations (d) Short latent period

5. Exposure to vinyl chloride leads to (a) Angiosarcoma of the liver (b) Laryngeal tumour (c) Nasal cancer (d) None of the above

6. Aromatic amines lead to carcinoma of (a) Bladder (b) Lung (c) Nasal Septum (d) All of above

7. By ILO definition, Pneumoconiosis is ________________ (a) accumulation of dust in the lung (b) Tissue reaction to its presence. (c) a & b (d) Any damage to lung

8. Which is not true of silicosis (a) Clinical manifestations are shortness of breath (b) The dust must contain silica in a free state as quartz (SiO2) and the particles must be of respirable size. (c) No X ray changes (d) Wet processes carry less risk or none at all but dry processes are definitely dangerous

9. “Asbestos bodies” are seen in (a) Sputum (b) X-ray (c) Clinical examination (d) None of the above

10. Ground glass appearance on X ray is seen in (a) Asbestosis (b) Silicosis (c) Anthracosis (d) Berylliosis

11. Caplan’s syndrome is seen in (a) Asbestosis (b) Silicosis (c) Anthracosis (d) Berylliosis

12. Byssinosis is caused by exposure to (a) Cotton dust (b) Sugarcane dust (c) Tobacco (d) All of above

13. Level I safety audit is done (a) Once in a month (b) Once in two months (c) Once in three months (d) Fortnightly

14. Asbestosis causes all except (a) Mesothelioma (b) Calcified pleural plaque (c) Pneumoconiosis (d) Farmer’s lung

15. Farmer’s lung results from exposure to :- (a) Sugarcane dust (b) Cotton fibre dust (c) Grain dust (d) Tobacco

16. Micropolyspora faeni is the main cause for (a) Byssinosis (b) Bagassosis (c) Anthracosis (d) Farmer’s lung

17. Lead is the most used metal commonly in the industries because of : (a) Low boiling point (b) Anticorrosive (c) Least toxic (d) Easily mixes with other metals

18. Acceptable blood lead levels are: (a) 25 μg/100ml (b) 50 μg/100ml (c) 75 μg/100ml (d) 100 μg/100ml

19. Lead poisoning in industries commonly occurs by: (a) Inhalation (b) Ingestion (c) Skin absorption (d) Conjunctival route

20. Size of respirable dust is below (a) 0.1 micron (b) 1 micron (c) 5 micron (d) 10 micron

21. Toxic effects of inorganic lead exposure include all except: (a) Abdominal colic (b) Blue line on gums (c) Wrist drop (d) Mental confusion (e) Stippling of RBC

22. Safer Alternatives for benzene are (a) Toluene (b) Xylene (c) Trichloroethylene (d) Cyclohexane (e) All the above

23. Smell of ‘Bitter Almonds’ in the breath is seen in poisoning of (a) Hydrogen cyanide (b) Nitrous Fumes (c) Carbon – Monoxide (d) Trichloroethylene (Trilene)

24. Which one of the following is not the direct effect of heat exposure in an industry : (a) Heat exhaustion (b) Heat stroke (c) Erythrocyanosis (d) Burns

25. Canteen for workers as a welfare measure under Factories Act is a must when the strength of the workers is more than (a) 200 (b) 100 (c) 250 (d) 500

26. Which of the following statement is Not true for ESI (a) Funeral benefit up to a maximum of Rs 2500 (b) In result of employment injury, the dependents of an insured person are eligible for periodical payments (c) Disablement benefit @ 80% of wages (d) Maternity benefit for 12 weeks for confinement.

27. Which of the following is not a benefit to the employer in ESIC (a) No responsibility for the employee’s health (b) Exemption from applicability of Workmen’s Compensation Act 1923 (c) Healthy work force (d) Rebate under Income tax act

28. All of the following are notified under Factories act except (a) Asbestos (b) Nickel (c) Coal tar (d) Silica

29. Which of the following disease may be encountered as occupational hazard (a) Leptospirosis (b) Brucellosis (c) Anthrax (d) All of the above

30. All the following are pneumoconiosis except : (a) Siderosis (b) Bagoasosis (c) Farmers’s lung (d) Psittacosis

31. Pneumoconiosis is caused by all except (a) Coal dust (b) Silica (c) Chromium (d) Asbestos

32. The ESI Act came into being in : (a) 1948 (b) 1952 (c) 1962 (d) 1975

33. ESI corporation works under:- (a) Ministry of Labour (b) Ministry of Health (c) As autonomous body (d) Respective state government.

Answers : (1) a; (2) a; (3) d; (4) d; (5) a; (6) a; (7) c; (8) c; (9) a; (10) a; (11) c; (12) a; (13) c; (14) d; (15) c; (16) d; (17) b; (18) c; (19) a; (20) c; (21) d; (22) e; (23) a; (24) a; (25) c; (26) b; (27) a; (28) b; (29) d; (30) d; (31) c; (32) c; (33) c.

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