Part 2 Injury and Disease Prevention

Learning outcomes:• Recognise the physical form of a substance to the

related health hazard• Distinguish the relationship between the route of entry

into the body of a hazardous substance and associated risks

• Distinguish between acute and chronic ill-health effects• Acquire a basic understanding of exposure limits• Apply a hierarchy of control measures to reduce the risk

of ill-health caused by exposure to chemical or biological agents

• Outline the basic principles relating to the disposal of waste and the control of atmospheric pollution.

Forms of Chemical AgentsA chemical may be in the form of :1. A substance

A substance is a chemical element or a compound, including any impurities.

2. A preparationA preparation is a mixture of substances, usually with a deliberately proportioned composition.

(Note: Compounds are pure substances made of atoms of two or more elements chemically combined in

fixed ratios e.g. H2O, CO2).

Forms of Chemical Agents• Liquids (harmless to highly toxic corrosive acids and alkalis)

• Gases (formless chemical where its volume and state can be changed by the combined effect of increased pressure and decreased temperature)

• Vapours (gaseous form of a liquid below its boiling point)

• Mists (finely suspended droplets formed by condensation from a gas or the atomising of a liquid or from aerosols/created by many industrial processes e.g. car spraying)

• Fumes (fine particulate solids created by condensation from a vapour e.g. metal in molten state have metallic fumes – oxides produce highly toxic fumes)

• Dusts (solid particles of varying size/settle under gravity and accumulate/airborne under turbulence of air movement)

• Aerosol (fine suspension of solid particles or droplets in a carrier gas – the spray can).

Biological Agents and Hazards

Biological Agents will lead to biological hazards. These hazards relate mainly to illnesses contracted from exposure to harmful micro-organisms.

Forms of Biological Agents

• Fungi (a fungus is a plant lacking chlorophyll and reproducing by spores e.g. mushrooms, moulds and yeasts)

• Bacteria (a bacterium is any of a large group of single celled microscopic organism of various shapes and sizes e.g. bacilli (rod shaped), cocci (spherical), spirilla (spiral shaped) most of which may cause disease.

• Virus – known as acellular organism and a pathogenic agent, it multiplies rapidly inside a living cell. It is unable to grow or reproduce outside a host cell.

Main Classification of Substances hazardous to Health

• Various hazard communication standards are used in different countries

• Global Harmonisation of Systems for Classification of Chemicals (GHS) – United Nations backed.

• 2 basic “user groups” namely the actual USER and the TRANSPORTER/hauler.

Categories of Danger (the RISKS)associated with substances

• Physico-chemical effects caused by the intrinsic physical or chemical properties of the substance e.g. flammable, oxidising or explosive

• Health Effects – arising from a chemical causing harmful effects to living organisms (death, injury or adverse health effects) when ingested, inhaled or absorbed. Toxic effects may be acute or chronic e.g. cancer, local or systemic, and reversible or irreversible

• Environmental effects – relate to the potential of a chemical to damage one or more environmental compartments i.e. air, soil, water or groundwater.

Local Vs. Systemic

• A Local effect refers to an adverse health effect that takes place at the point or area of contact. The site may be skin, mucous membranes, the respiratory tract, gastrointestinal system, eyes, etc. Absorption does not necessarily occur. Examples: strong acids or alkalis.

• Systemic effect refers to an adverse health effect that takes place at a location distant from the body's initial point of contact and presupposes absorption has taken place. Examples: arsenic effects to the blood, nervous system, liver, kidneys and skin; benzene effects to the bone marrow.

• Substances with systemic effects often have "target organs" in which they accumulate and exert their toxic effect.

Acute and Chronic Health Effects

• Acute - quantity of a toxic or harmful substance absorbed into the body produces harmful effects very quickly (within seconds, minutes or hours)

• Chronic – harmful effects of a substance absorbed into the body take a very long time to appear (months or years)

Health Effects• Toxic (e.g. potassium cyanide, carbon monoxide)• Corrosive (e.g. Acids and Alkalis, Gases and Vapours)• Irritant (e.g. dust, pollen, ultraviolet light)• Sensitising ( substances or preparation causing allergic

reactions)• Carcinogenic (cancer bearing substances and

preparation)• Mutagenic (alter cell development and causes changes

in future generation)• Toxic to Reproduction (“Reprotoxic” – affect male or

female fertility, harm caused to foetus or may cause abnormal development of an embryo resulting in birth defects ( substances called Teratogens)

(NOTE : Ref. the last 3 is collectively known as the “CMR” effects).

Bacteria• In human hosts, certain types of bacteria can

cause tetanus, pneumonia, syphilis, tuberculosis and other illnesses. As long as the host is not infected with antibiotic resistant bacteria, they can be treated with antibiotics, which kill bacteria or at least hamper their growth. Antiseptics, sterilization and disinfectants can help prevent contamination and risk of infection from bacteria.

• The term “friendly bacteria” is used to describe the types of bacteria that offer some benefit. Not only does bacteria help produce the food we eat and keeps the soil fertile, it also helps us digest our food. Bacteria in our digestive system help to convert milk protein into lactic acid and inhibit the growth of potentially harmful bacteria.

Legionella• Legionella organisms are readily found in natural

aquatic bodies and some species have been recovered from soil. The organisms can survive in a wide range of conditions, including temperatures of 0 to 63o C, pH of 5.0 to 8.5, and dissolved oxygen concentrations of 0.2 to 15 ppm in water.

• Temperature is a critical determinant for Legionella proliferation.

• The bacterium may be spread by aerosols from contaminated water source. It affects the lungs and is deposited in the aveoli and can be fatal.

Zoonoses• A zoonosis (pronounced /zoʊəˈnoʊsɪs/) is any

infectious disease that is able to be transmitted (by a vector) from other animals, both wild and domestic, to humans or from humans to animals.

e.g. ANTHRAX - caused by the bacterium Bacillus anthracis which is highly lethal in some forms and BRUCELLOSIS also known as undulant fever, undulating fever, or Malta fever - primarily a disease of domestic animals (goats, pigs, cattle, dogs, etc) and humans and has a worldwide distribution, mostly now in developing countries.

Bronchitis

• Bronchitis is an acute inflammation of the air passages within the lungs. It occurs when the trachea (windpipe) and the large and small bronchi (airways) within the lungs become inflamed because of infection or other causes.

• The thin mucous lining of these airways can become irritated and swollen.

• The cells that make up this lining may leak fluids in response to the inflammation.

• Coughing is a reflex that works to clear secretions from the lungs.

Your Airways and Lungs

Pneumonia

• Pneumonia is an inflammation of the lung, usually caused by an infection. Three common causes are bacteria, viruses and fungi. You can also get pneumonia by accidentally inhaling a liquid or chemical.

• The best preventive measures include washing your hands frequently, not smoking, and wearing a mask when cleaning dusty or moldy areas.

Addiction (to Tobacco)• Addiction was a term used to describe a devotion,

attachment, dedication, inclination, etc. Nowadays, the term addiction is used to describe a recurring compulsion by an individual to engage in some specific activity, despite harmful consequences to the individual's health, mental state or social life.

• Tobacco smoke contains nicotine and harmane (inhibitor), which combined give rise to addictive stimulant and euphoriant properties. The effect of nicotine in first time or irregular users is an increase in alertness and memory, and mild euphoria.

• Nicotine also disturbs metabolism and suppresses appetite. This is because nicotine, like many stimulants, increases blood sugar levels.

Harmful Chemicals in Tobacco

ASTHMAASTHMA is a disease that affects the breathing passages of the lungs (bronchioles). Asthma is caused by chronic (ongoing, long-term) inflammation of these passages. This makes the breathing passages, or airways, of the person with asthma highly sensitive to various "triggers."

When the inflammation is "triggered" by any number of external and internal factors, the passages swell and fill with mucus.

Muscles within the breathing passages contract (bronchospasm), causing even further narrowing of the airways.

This narrowing makes it difficult for air to be breathed out (exhaled) from the lungs.

This resistance to exhaling leads to the typical symptoms of an asthma attack.

Because asthma causes resistance, or obstruction, to exhaled air, it is called an obstructive lung disease. The medical term for such lung conditions is Chronic Obstructive Pulmonary Disease or COPD.

Virus

• A virus is basically a tiny bundle of genetic material - either DNA or RNA- carried in a shell called the viral coat, or capsid, which is made up of bits of protein called capsomeres. Some viruses have an additional layer around this coat called an envelope.

• When viruses come into contact with host cells, they trigger the cells to engulf them, or fuse themselves to the cell membrane so they can release their DNA into the cell.

• Once inside a host cell, viruses take over its machinery to reproduce. Viruses override the host cell’s normal functioning with their own set of instructions that shut down production of host proteins and direct the cell to produce viral proteins to make new virus particles.

• Viruses cause a number of diseases in eukaryotes. In humans, the common cold, chickenpox, influenza, shingles, herpes, polio, rabies, and AIDS (Acquired Immune Deficiency Syndrome) are examples of viral diseases.

• Because viruses can transfer genetic material between different species of host, they are extensively used in genetic engineering.

What is a VECTOR?

West Nile Virus

West Nile virus (or WNV) is a Virus of the family Flaviviriades; part of the Japanese encephalitis (JE) antigenic complex of viruses. It is found in both tropical and temperate regions. It mainly infects birds, but is known to infect humans, horses, dogs, cats, bats, chipmunks, skunks, squirrels, and domestic rabbits. The main route of human infection is through the bite of an infected mosquito.

HIV and AIDS

• HIV stands for Human Immunodeficiency Virus.  HIV is a virus that takes over certain immune system cells to make many copies of itself.  HIV causes slow but constant damage to the immune system.

• AIDS stands for Acquired Immune Deficiency Syndrome. 

• AIDS is the condition diagnosed when there are a group of related symptoms that are caused by severe HIV infection.  AIDS makes the body vulnerable to life-threatening illnesses called opportunistic infections.

How is HIV transmitted?

• HIV is transmitted through four (4) body fluids:  blood, semen, vaginal fluid, and breast milk.  In order to pass HIV from one person to another, HIV-infected fluid from one person needs to get into the bloodstream of another person. 

• HIV is usually transmitted through sharing needles, unprotected anal, vaginal, and sometimes oral sex, and from mother to infant before or during delivery or while breastfeeding.

AIDSAIDS stands for Acquired Immune Deficiency Syndrome:

Acquired means you can get infected with it;

• Immune Deficiency means a weakness in the body's system that fights diseases.

• Syndrome means a group of health problems that make up a disease.

• AIDS is caused by a virus called HIV, the Human Immunodeficiency Virus. If you get infected with HIV, your body will try to fight the infection. It will make "antibodies," special molecules to fight HIV.

• A blood test for HIV looks for these antibodies. If you have them in your blood, it means that you have HIV infection. People who have the HIV antibodies are called "HIV-Positive."

How do you get AIDS?

Most people get the HIV virus by:

• having sex with an infected person

• sharing a needle (shooting drugs) with someone who's infected

• being born when their mother is infected, or drinking the breast milk of an infected woman.

Opportunistic Infections (CDC/USA)

HIV disease becomes AIDS when your immune system isseriously damaged. If you have less than 200 CD4 cells orif your CD4 percentage is less than 14%, you have AIDS.

• PCP (Pneumocystis pneumonia), a lung infection; • KS (Kaposi’s sarcoma) a skin cancer; • CMV (Cytomegalovirus), an infection that usually affects

the eyes • Candida, a fungal infection that can cause thrush (a

white film in your mouth) or infections in your throat or vagina

AIDS-related diseases also includes serious weight loss,brain tumors, and other health problems. Withouttreatment, these opportunistic infections can kill you.

Is there a CURE for AIDS?

There is no cure for AIDS. There are drugs

that can slow down the HIV virus, and slow

down the damage to your immune system.

There is no way to "clear" the HIV out of

your body (as of today).

Routes of Entry into the Body

• Inhalation (inhaled substances e.g. dust Vs. respirable substances e.g. vapours and gases/depending on size of particles)

• Ingestion (entry through the mouth, to the stomach and intestines/contaminated food and drinks)

• Absorption (entry though the skin or via the eyes)

• Aspiration (process whereby liquids or solids go direct into the lungs other than by inhalation)

• Injection (entry into the body by high pressure equipment or contaminated sharp objects).

The Epiglottis and Aspiration

Body Defences Against Hazardous SubstancesNatural defences include:

1. Airway Filtration (moist hair in the nose/the sinuses/mucous tissue)

2. Lachrymation (tear production/eyelids/eyebrows/secretion dilute irritants)

3. Immune Response (permeable epidermis/sensitised lymphocytes-repeated exposure/inflammation)

4. Inflammatory Response (defensive process but can result in disease/reaction of tissue to a harmful agent insufficient to kill the tissue/occurs when foreign body enters the body by way of inhalation, ingestion, absorption, pervasion, implantation, surface penetration, trauma, energy transformation).

Workplace Exposure Limits(WELs)

• WELs provide the basis for controlling airborne contaminants

• Ideally, “No Exposure” limit is the best possible strategy

• If not reasonably practicable, it must be adequately controlled (limitation of the risk).

International Variations

• Occupational Exposure Limit (OEL) is used in the UK

• Threshold Limit Value (TLV) is used in the USA

• Indicative Limit Value (ILV) – EU countries

• Maximum Allowable Concentration (MAC).

Measuring Exposure in Units

• Parts per million (ppm)

• Milligrams per cubic metre of air (mg/m3 or mgm3)

• Fibres per millimetre of air e.g. asbestos

Long Term and Short Term Limits

Depends on two (2) factors:

• the nature of the substance

• the length of the exposure

Long Term and Short Term Exposure Limits

• Long Term Exposure Limit is the level of airborne contaminant allowable over an eight (8) hour period, used for substances producing chronic effects

• Short Term Exposure Limit (15 minutes) is the level of airborne contaminants allowable over a 15 minute period, used for substances producing acute effects.

Concentration Levels

It is expressed as time weighted averages

(TWA), meaning that measurements are

taken over the period in question and the

airborne concentration are then averaged

out.

Below is a graph of concentration over an

8-hour day at a hypothetical workplace.

Monitoring AIR QUALITY• Sampling Techniques (location/method of

analysis/frequency of the sampling)• Stain Tube Detectors (analysing gaseous

contamination of the workplace/types include Draeger Multigas Detector, Automatic Multigas Detector, Polytest Tubes and Toxicated Gas Detectors)

• Passive Samplers (Dish type and Tube type to sample concentration of airborne pollutants)

• Smoke Tubes (assess the strength and direction of air flow)

Gas Detector

Passive Samplers (dish type with absorbent material)

Limitations of Exposure Limits

• designed only to control the absorption into the body of harmful substances following inhalation (not concerned with absorption following ingestion or through control with skin and eyes)

• take no account of human sensitivity or susceptibility• take no account of the synergistic (or combined) effects

of mixtures of substances• no sharp dividing line between “safe” and “dangerous”

conditions• cannot be applied to working periods (shifts with

overtime) over the 8 hour period• change in temperature, humidity or pressure may

increase the harmful potential of a substance.

Control Measures (Prevention)

The following hierarchy is widely acceptedwhen we address control measures:

• Eliminate the hazard• Use physical or engineering controls which

reduce the risk at source • Provide protection generally rather than

individually• Control the risks to the person by job design,

management, or (as a last resort) personal protective equipment.

Elimination or Substitution of Hazardous Substances

Elimination

• requires careful examination of the work activity and process

• appropriate risk assessment must be carried out• replacement with materials which do the same

job but present no risk to health• must understand the properties and behaviour of

alternative substances and material.

Elimination or Substitution of Hazardous Substances

SubstitutionIf eliminating the risk is not practicable, the nextoption is to reduce the risk by substituting thehazard with a different one with less potential forharm.• using the same material but in a different physical

form (e.g. granulated pottery dlazes rather than powders)

• Using a similar, but different substance altogether, such as one with a lower volatility and/or higher WEL.

Elimination or Substitution of Hazardous Substances

Process Changes• may demand changes in work methods

(e.g. vacuuming rather than sweeping)Reduced Time Exposure• two (2) methods to achieve i.e. provide

regular breaks and job rotation.Enclosure and Segregation• total enclosure or containment of the

hazard (using remote control robots)

Elimination or Substitution of Hazardous Substances

Local Exhaust Ventilation (LEV)

• ideal to control dusts, vapours and fumes generated from a point source

• some examples of LEVs are Fume Cupboards (used in laboratories), Captor hoods, Glove boxes and Receptor hoods.

A Fume Cupboard

Fume Cupboard Extraction

Elimination or Substitution of Hazardous Substances

Dilution Ventilation• operates simply by diluting the contaminant

concentration in the general atmosphere to an acceptable level (i.e. below the WEL) through the usage of extracting fans

• two (2) important criteria have to be considered i.e. the rate of contaminant generation and the position of the extraction fan.

Elimination or Substitution of Hazardous Substances

Respiratory Protective Equipment• Respirators • Breathing Apparatus • Half Mask Respirator (single or twin cartridge)• Full Face or Canister Respirator

(Note: Breathing Apparatus include Fresh air hose apparatus, Compressed Airline apparatus and Self-contained apparatus).

Elimination or Substitution of Hazardous Substances

Other Protective Equipment and Clothing

• Gloves

• Overalls

• Eye Protection (spectacles, goggles, face visors)

Basic Environmental Issues

There are three (3) broad classes of

pollution :

• Atmospheric pollution (fumes, smoke, dust – the by-products of industrial processes)

• Water pollution (liquid wastes (effluent) comprising toxic substances, etc)

• Land pollution (solid waste from industrial processes deposited on land).

Control of Atmospheric Pollution

• Legislation and enforcement (checks on emission limits)

• Permits from governing body e.g. DOSH

• Form of abatement technology (change-out, scrubbers)

Other Forms of Control

• Government Legislation (prosecution)

• By-Laws (set by the local council/compound)

• Education (personal hygiene/social responsibility)

• Re-cycling (industrial wastes)

Disposal of Waste and Effluent

The hierarchy of waste management optionsare :• Waste reduction (process change and

optimizing process efficiency)• Re-use e.g. glass bottles• Recovery of waste (i.e. recycling/old

newspapers, old tires for rethreading,)• Disposal (generally to landfill away from

dwelling settlement).

Air Quality Index

Air Quality I ndex (AQI ) Values

Levels of Health Concern Colors

When the AQI is in this range: ..air quality conditions are: ...as symbolized by this color:

0-50 Good Green

51-100 Moderate Yellow

101-150 Unhealthy for Sensitive Groups Orange

151 to 200 Unhealthy Red

201 to 300 Very Unhealthy Purple

301 to 500 Hazardous Maroon

Do your part to help waste disposal

Part 3 – Injury

What is DPI?

Discomfort, pain and injury (DPI) covers

many conditions of the muscles and bones

which include: 

• Gradual process injuries (GPI/work related)

• Simple back pain (Back Injury)

• Strains and Sprains.

Contributory Factors and the Combined Effects

There are many factors that work together, in varying

proportions to cause DPI.

Soft Tissue Injury

Soft tissue injury is damage of the soft tissue ofthe body. These types of injuries are a majorsource of pain and discomfort.

• The four fundamental tissues that are affected are the muscles, ligaments, tendons and nerves.

• Management of soft tissue injuries consists of protecting the injured tissue; resting it with splints, braces, or tape; ice; compression; and elevation.

Common Causes of Soft Tissue Injury

• Soft tissue injury is caused by direct or indirect trauma

• Direct trauma may happen in connection with sports or other accidents, being struck by an object or falling

• Indirect trauma commonly stems from overuse of the tissue ( assembly line or factory workers often suffer from this type because of the many repetitive movements they have to do many times a day).

Types of Soft Tissue Injury

Soft tissue injuries include ligament sprains

(e.g. sprained ankle), tendon strains,

repetitive stress injury and carpal tunnel

syndrome.

Treatment Options

Treatment options might include:

• Physiotherapy exercises to promote healing, strength and flexibility

• Electrotherapy

• Manual techniques such as mobilization and massage.

The Healing Phases

In general, the injury will heal in phases:

• The first phase typically lasts 72 hours and is marked byswelling, redness, warmth and pain.

• The second phase is the repair phase and lasts 48 hours to six weeks. During this time, the body will create scar tissue (collagen), and you may experience pain and/or discomfort.

• The third is most important phase and is called the remodeling phase because the collagen is remodeled to replicate the damaged tissue. This phase will last three weeks to one year or more.

• Severe injuries where the tissue has completely ruptured require surgery to sew the torn pieces back together.

Spinal Cord Injury

• Spinal cord injury (also known as “myelopathy” or SCI) is a life-altering injury to the spinal cord that results in the loss of feeling and mobility.

• A “complete spinal cord injury” means that there is no voluntary movement or physical sensation below the injury. Both sides of the body are affected equally.

• An “incomplete spinal cord injury” means that some movement or sensation below the injury is possible. Both sides of the body are not necessarily affected equally.

Common Causes Spinal Cord Injury

• The two most common causes of spinal cord injury are trauma and diseases

• Trauma may be caused by slips and falls, diving accidents, gun shot wounds or other disruptions of the spinal cord

• Diseases such as polio, spina bifida and tumors may also cause spinal cord injury.

Slip and Fall Injury

A "slip and fall" or "trip and fall" is the generic term for an injury which occurs when someone slips, trips or falls as a result of a dangerous or hazardous condition.

Burn Injuries

• Burn injuries result from a number of different causes and can range from minor to life threatening.

• A burn injury is defined as damage to the skin or other organ from contact with heat, radiation, electricity or chemicals.

Severity or Burn Depth

The severity of burn injuries are classified by the depth ofthe burn in three different degrees: first, second, and third.

• First degree burns cause minor tissue damage only to the outer skin layer. The burn is painful, leaving the skin reddish and dry with little swelling.

• Second degree burns damage the first two layers of skin. There is severe pain and blistering (bubbling). The skin is moist, red, and swollen with minimal scarring.

• Third degree burns damage all layers of skin and may also damage fat, muscle and bone tissue. The damaged skin often is left depressed, charred, and leathery. Initially there may be little pain due to the destruction of nerve endings.

Causes of Burn Injury• Burn injuries fall into four (4) categories with the most

common causes being, scalding hot and flammable liquids and fires

• Thermal/contract burns – occur when the body comes into contact with hot items, such as hot metals, scalding liquids, steam and flames

• Radiation (ultraviolet) burns – are caused by prolonged exposure to the ultraviolet rays of the sun (sunburns), as well as tanning booths or beds

• Chemical burns – result from skin or eye contact with strong acids (i.e., sulfuric acid) and bases, such as alkaloids

• Electrical burns – result from the electrical current flowing through the body

• Inhalation burns – result from breathing fumes or smoke during a fire.

Skin Injuries - Blisters

Blisters are caused by injury, allergic reactions, orinfections, which may include the following:

• burns/scalds • sunburns • friction (from a shoe, for example) • contact dermatitis (irritation or inflammation

caused by a foreign substance)• impetigo (a contagious infection of the skin

caused by streptococcus bacteria) • viral infections (including chickenpox and herpes

zoster)

Impetigo

Herpes Zoster

Herpes zoster, or shingles, is caused by the same virus that causes chickenpox. After an episode of chickenpox, the virus becomes dormant in the body. Herpes zoster occurs as a result of the virus re-emerging after many years.

Herpes Zoster

Injury and Hearing LossAn injury to the ear may cause temporary or permanent hearing loss.You can be injured by a variety of forces, including:

• A blow, cut, or other trauma to the ear or ear canal. This may cause bleeding and infection, which can result in temporary hearing loss. A trauma may also damage the inner ear or cochlea, which can result in permanent hearing loss.

• Strenuous coughing, sneezing, or nose-blowing, or a strenuous bowel movement.

• A sudden, dramatic change in air pressure, such as occurs in scuba diving or air travel. This may put too much stress on the eardrum or other middle ear structures, resulting in bleeding or fluid imbalance in the middle and inner ear. This type of injury is called barotrauma.

• A blow to the head. A blow may change the position (dislocation) of the three bones of the middle ear (ossicle dislocation). A head injury may also cause a ruptured eardrum (tympanic membrane perforation).

• A sudden, extremely loud noise (such as an explosion, gunshot, or firecracker). This is called acoustic trauma.

Hearing Loss

1. Conductive Hearing Loss e.g. vibrations, sudden loud noise, abnormal bone growths, wax hardened causing blockage.

2. Sensorineural Hearing Loss from head injury, birth defects, high blood pressure.

3. Presbycusis due to ageing affecting the inner ear.4. Noise-induced hearing loss (NIHL) - this is hearing

loss due to exposure to either a sudden, loud noise or exposure to loud noises for a period of time. A dangerous sound is anything that is 85 dB (sound pressure level - SPL) or higher.

5. Drug induced - some medications can result in damage to the auditory system with prolonged use. They are called ototoxic.

The EAR

Eye Injuries

Eye injuries range from the very minor to severeInjuries such as:

• Acids (such as sulfuric acid found in car batteries) or alkalis (such as lye found in drain cleaner and ammonia) can splash into your eyes causing burning sensation

• Corneal abrasions (scratch)• Light induced injuries• Foreign bodies in the eye• Subconjunctival Hemorrhage (rupture of blood

vessel).

Eye Diseases

• Cataracts (clouded lenses)

• Glaucoma (damage to the optic nerve from too much pressure in the eye)

• Retinal Disorders (problems with the nerve layer at the back of the eye)

• Conjunctivitis (a viral/bacterial infection also known as pink eye)