Environmental healthEnvironmental health

• Definition: “the control of all those Definition: “the control of all those factors in man’ s physical factors in man’ s physical environment which exercise or may environment which exercise or may exercise a deleterious effect on his exercise a deleterious effect on his physical development, health and physical development, health and survivalsurvival

WHO organizationWHO organization

• Define health as a state of complete Define health as a state of complete physical , mental and social well physical , mental and social well being, not only the absence of the being, not only the absence of the disease or infirmitydisease or infirmity

Practice of environmental Practice of environmental healthhealth • Water sanitationWater sanitation• Refuse and garbage disposalRefuse and garbage disposal• Sewage disposalSewage disposal• Air pollution (indoor and out door)Air pollution (indoor and out door)• InjuriesInjuries• Food hygieneFood hygiene• Vector controlVector control• Safety and health in hospitalSafety and health in hospital

• Environment includes all those Environment includes all those factors related to health that are factors related to health that are external to human body, the external to human body, the individual has a limited control over individual has a limited control over these factors.these factors.

Health hazards are classified as:Health hazards are classified as:

Chemical, physical ,biological social Chemical, physical ,biological social and behavioural.and behavioural.

Aim and objectivesAim and objectives

• To inform or enlighten students about To inform or enlighten students about general health hazards in the environment general health hazards in the environment such as,,,,,,,, such as,,,,,,,,

• To be able at primary level to protect and To be able at primary level to protect and prevent diseases due to pollution of water ,air prevent diseases due to pollution of water ,air and food and food

• To develop awareness among medical To develop awareness among medical students regarding currently emerging students regarding currently emerging diseases related to environment such as bird diseases related to environment such as bird flue incidents and dengue fever……..flue incidents and dengue fever……..

Solid wastesSolid wastes

• Solid wastesSolid wastes

• DefinitionDefinition: “Solid wastes” is applied : “Solid wastes” is applied to unwanted or discarded waste to unwanted or discarded waste materials from houses, street materials from houses, street sweepings, industrial and agricultural sweepings, industrial and agricultural operations arising from man’ operations arising from man’ activities.activities.

Health aspectsHealth aspects

• The organic portion of solid wastes ferments and The organic portion of solid wastes ferments and favor fly breedingfavor fly breeding

• The garbage in the refuse attracts ratsThe garbage in the refuse attracts rats• The pathogens may conveyed to man through The pathogens may conveyed to man through

flies and dustflies and dust• There is possibility of water pollution if rain water There is possibility of water pollution if rain water

passes through deposits of fermenting refusepasses through deposits of fermenting refuse• There is risk of air pollution, if there is accidental There is risk of air pollution, if there is accidental

or spontaneous combustion of refuseor spontaneous combustion of refuse• Piles of refuse are nuisance from aesthetic point Piles of refuse are nuisance from aesthetic point

of viewof view

Sources of refuseSources of refuse

• Sources and types of refuse:Sources and types of refuse:

• 1:Street refuse 1:Street refuse

• 2:Market refuse 2:Market refuse

• 3:Stable litter3:Stable litter

• 4:Industrial refuse4:Industrial refuse

• 5:Domestic refuse5:Domestic refuse

• 6:Agricultural6:Agricultural

Types of refuseTypes of refuse

• Ashes: residues of combustion of solid fuelsAshes: residues of combustion of solid fuels• Garbage: decomposable wastes from food Garbage: decomposable wastes from food • Rubbish : Non decomposable wastesRubbish : Non decomposable wastes• DebrisDebris• Dead animalsDead animals• Hazardous wastes: “wastes that pose a Hazardous wastes: “wastes that pose a

potential hazards to humans or other living potential hazards to humans or other living organisms because these wastes are non organisms because these wastes are non degradable or persistent in naturedegradable or persistent in nature

Collection and disposalCollection and disposal

• IncinerationIncineration

• Open dumpingOpen dumping

• Domestic grinding for garbageDomestic grinding for garbage

• Controlled dumping or Sanitary land Controlled dumping or Sanitary land fillsfills

• CompostingComposting

• RecyclingRecycling

Advantages and Advantages and disadvantages of the disadvantages of the incineration incineration • Combustion of breeding materialsCombustion of breeding materials

• Takes combined garbage and refuseTakes combined garbage and refuse

• Can be very efficient and 24 h/day in Can be very efficient and 24 h/day in large cities.large cities.

• Cause air pollution, particulates and Cause air pollution, particulates and odourodour

• High capital investment, high High capital investment, high operational and maintenance cost operational and maintenance cost

Advantages and disadvantages Advantages and disadvantages of open dumpingof open dumping

• Hauling is only costHauling is only cost

• Combined garbage and rubbishCombined garbage and rubbish

• Optimum for insects and rodents Optimum for insects and rodents breedingbreeding

• Air pollution from dump firesAir pollution from dump fires

• Water pollution from leachingWater pollution from leaching

Sanitary landfillsSanitary landfills

AdvantagesAdvantages

• Combined collectionCombined collection

• Low capital investmentLow capital investment

• Moderate operational costModerate operational cost

• Land reclamation for restricted useLand reclamation for restricted use

• Adopted for small townsAdopted for small towns

• DisadvantagesDisadvantages

• Land requirementLand requirement

• Require selected soil and coverRequire selected soil and cover

• Require stand by fire controlRequire stand by fire control

• leaching may add pollutant to leaching may add pollutant to ground or surface water sourcesground or surface water sources

compostingcomposting

• AdvantagesAdvantages

• Conserves and recycles wastesConserves and recycles wastes

• Provides humus for soil Provides humus for soil

• Decomposition heat control fliesDecomposition heat control flies

• Aerobic action free of odourAerobic action free of odour

• Sewage sludge can be combinedSewage sludge can be combined

• DisadvantageDisadvantage

• Require pre-sorting and grinding.Require pre-sorting and grinding.

• High capital investment and High capital investment and maintenance cost.maintenance cost.

• Require assured market for compost.Require assured market for compost.

• Require disposal of non Require disposal of non compostablescompostables

Advantages and disadvantages Advantages and disadvantages of recyclingof recycling

• Recovery of usable and salable materials.Recovery of usable and salable materials.

• Conservation for energyConservation for energy

• Limited to special wastes and selected Limited to special wastes and selected materialsmaterials

• At the mercy of the marketAt the mercy of the market

• Require special equipments.Require special equipments.

• Remainder must be managedRemainder must be managed

Sewage disposal (excreta Sewage disposal (excreta disposal)disposal)

• Proper disposal of sewage is a Proper disposal of sewage is a fundamental environmental health fundamental environmental health service without which there cannot be service without which there cannot be any state of improvement in the state of any state of improvement in the state of community health.community health.

• Human or animal excreta is a source of Human or animal excreta is a source of transmission of several diseases such transmission of several diseases such as typhoid and paratyphoid fever, as typhoid and paratyphoid fever, diarrhoeas, cholera, ascariasis, viral diarrhoeas, cholera, ascariasis, viral hepatitis ……hepatitis ……

Treatment of sewage Treatment of sewage

• Primary treatmentPrimary treatment

• ScreeningScreening

• Removal of gritRemoval of grit

• Plain sedimentation..Plain sedimentation..

• Secondary treatmentSecondary treatment

• Trickling filterTrickling filter

• Activated sludgeActivated sludge

• Digestive sludgeDigestive sludge

Basis of sewage treatmentBasis of sewage treatment

• Protection of water supplies.Protection of water supplies.

• Protection of human food to be eaten Protection of human food to be eaten rawraw

• Protection of shellfish and other Protection of shellfish and other aquatic life.aquatic life.

• Protection of soil against pollutionProtection of soil against pollution

Environmental protection Environmental protection agency (EPA)agency (EPA)

• Independent agency of USA governmentIndependent agency of USA government

• Established 1970 to protect the environmentEstablished 1970 to protect the environment

• Establish standards for the quality of air and Establish standards for the quality of air and water .water .

• inspection and monitoring of radiation levels inspection and monitoring of radiation levels in the environmentin the environment

• Monitoring global warmingMonitoring global warming

• Regulation and legislation for handling and Regulation and legislation for handling and

Disposal of radio active materialsDisposal of radio active materials