Unit 8 – Public HealthEnvironmental Issues in Public

Health: Part I

Chapter 19 – A Clean Environment: The Basis of Public Health

Role of Government in Environmental HealthEnvironment is beyond the control of

individualsLocal governments provide clean water

and disposal of wastesAs population grew, environmental

problems transcended local government1960s and 1970s – state and federal

governments took more responsibilityNow, world population growth has led to

global environmental problems

Environmental HazardsRadiationMercuryLeadAsbestosPesticides and industrial chemicalsFederal government does research, sets

standards for exposure limitsEnvironmental Protection Agency (EPA)

RadiationUltraviolet light from the sun – skin

cancer and melanomaRadon gas – natural radioactivity – lung

cancer?Early scandals with patent medicines and

radium led to regulationX rays used in medicine and dentistry Lessons on health effects of radiation

learned from atomic bombings in Japan

MercuryNeurological damage in workersMinamata, JapanEmissions from coal-burning power plants in

US leads to air pollution, water pollution, contamination of fish

Concern about fever thermometers, school laboratory equipment

LeadHarmful to brain and nervous system,

especially of childrenContamination of drinking water by lead

pipes and lead solder for copper pipesAir pollutant from use in gasoline until

banned in the 1980sWas used in paint until 1977 – still a

threat in old housing – peeling paint or contaminated dust

Young children should be screened for blood lead levelsPermissible levels have been steadily lowered

AsbestosWas widely used because of fire resistanceUsed in insulation; still used in roofing, gaskets,

brake liningsWas required in schools between 1940 and 1973

Still a danger from deteriorating walls and ceilingsFibrous dust causes scarring of lungs

(asbestosis) and mesothelioma (cancer)Affected asbestos workersManville Corporation bankrupt – 1982Libby, Montana – whole area affected from

minesWorld Trade Center – clean-up and rescue

workers

Pesticides and Industrial ChemicalsRachel Carson’s Silent Spring – 1962 –

beginning of environmental movementDDT and other pesticides– now bannedPCBs – industrial uses

Hudson River – contaminates fishYusho accident (Japan) – contamination of cooking

oil – other similar accidentsProduction halted in US by 1977

Endocrine disrupters, affect reproduction, nervous system, immune system, maybe cancer

Soluble in fat, persist in environment, very stable

Occupational ExposuresWorkers are often the first to suffer effects of an

exposure – serve as guinea pigsCarcinogens recognized through occupational

cancersScrotal cancer in chimney sweepsBladder cancer in dye factory workersLung, lymphatic cancer from arsenic (copper smelters)Angiosarcoma from vinyl chloride (plastics)

Neurotoxins also recognized through occupational illnessHexane (shoemakers), trichloroethylene (dry

cleaners), pesticide applicators.

Factory FarmsAnimals crowded together and tended by

automated systemsProduce huge volumes of wastes – lagoonsAir pollution (ammonia, hydrogen sulfide,

methane) and water pollution after rainPolitical power protects them from

environmental regulation

Setting StandardsMost chemicals have not been tested for

health effectsOccupational Safety and Health ActToxic Substances Control ActFederal Insecticide, Fungicide, and

Rodenticide ActClean Air ActProcess of standard setting is slow and

always controversial

Risk-Benefit AnalysisAbsolute safety is impossibleOver-regulation can cause under-regulationMust balance risk against other societal

goals, including economic well-beingCurrent administration and Congress favor

economic and business interests over environment and public health

Unit 8 – Public HealthEnvironmental Issues in Public

Health: Part I

Chapter 20 – Clean Air: Is It Safe to Breathe?

Air Pollution EventsWeather inversion in London, 1952 – more

than 4,000 deathsDonora, Pennsylvania in 1948 – similar

weather inversion Smog in Los Angeles in 1950s and 1960sClean Air Act of 1970

Criteria Air PollutantsParticulate matterSulfur dioxideCarbon monoxideNitrogen oxidesOzoneLead

Particulate MatterProducts of combustionFirst regulated total particulatesSix Cities Study – death rates higher in

most polluted citiesSmaller particles penetrate deeper into

lungs1987 set standards for PM10

1997 set standards for PM2.5

Lung cancer, other lung diseases, heart disease proportional to PM2.5

Sulfur DioxideCombustion of sulfur-containing fuels,

especially coalIrritates respiratory tractAcid rain

Nitrogen oxidesMotor vehiclesResponsible for yellowish-brown smogIrritates respiratory tractAcid rainContribute to ozone formation

OzoneProduced by sunlight acting on other air

pollutantsIrritating to eyes and respiratory systemIncreases mortality from cardiovascular and

respiratory diseases

LeadDamages nervous system, blood, and kidneysWas used in leaded gasoline, banned in

1980sHas decreased dramatically as an air

pollutant

Other Air PollutantsClean Air Act directed EPA to set standards

for 188 othersAs of 1993, only acted on asbestos, mercury,

beryllium, benzene, vinyl chloride, arsenic, radionuclides, coke oven emissions

Controversy over each standard

Strategies for Motor VehiclesTailpipe emissions limits

Catalytic convertersReformulated fuel

Vapor recovery systems on gasoline pumps

Inspection and maintenance requirementsRequirements that auto makers develop

zero emission vehiclesPublic transportationEncourage carpooling

Strategies for Industrial SourcesScrubbers on smokestacksLess polluting fuels (limit high-sulfur coal)Pollution allowances bought and soldNew Source Review

Industry has flouted the rulesLawsuits by statesBush Administration replaced this provision

with weaker “Clear Skies Initiative” Emergency Planning and Community

Right-to-Know Act

Good News54% decrease in air pollution since 1970California, with the worst pollution, has

instituted many special regulations and incentives, with some success

Indoor Air QualityMost people spend more time indoors than

outSources of indoor air pollution:

Tobacco smokeWood-burning stoves and fireplacesGas ranges and furnaces

Radon Danger is unclearSeeps up from soil and rockCan be sealed out

Formaldehyde from insulation, particleboard, plywood, some floor coverings and textiles

Indoor Air Quality, ctd.Formaldehyde from insulation, particleboard,

plywood, some floor coverings and textilesRegulated by Dept. of Housing and Urban

DevelopmentConsumer products such as pesticides, dry-

cleaning solvents, paints and paint thinners, hair spray, air freshenersShould be used with caution

Microbes such as legionella, hantavirusAllergens such as mold, house mites, animal

dander

Global Effects of Air PollutionAcid rain damages forests and crops, turns

lakes and rivers acidic, kills fish and plantsDepletion of the ozone layer

Montreal Protocol -- 1987Production of CFCs phased outOzone layer has stabilized

Carbon dioxide produced by burning fossil fuels causes greenhouse effect, global warming

Unit 8 – Public HealthEnvironmental Issues in Public

Health: Part I

Chapter 21 – Clean Water: A Limited Resource

Water Pollution IncidentsLake Michigan, Chicago – cholera -- 1885Minamata Bay, Japan – mercury – 1950sHudson River, New York – PCBs – 1970sLake Superior, Duluth – asbestos -- 1970s James River, Virginia – Kepone – 1960sCuyahoga River, Ohio – caught fire (oil) –

1969Lake Michigan, Milwaukee –

cryptosporidiosis -- 1993

Federal LegislationClean Water Act – 1972, 1977, 1987

Lakes and rivers should be fishable and swimmable

All pollution discharges should be eliminatedSafe Drinking Water Act – 1974, 1996

EPA should set standards for local systemsStates should enforce the standards

Clean Water ActPoint source pollution

Requirements for treating wastewaterSewage treatment plants or septic systemsTreat with chlorine or other disinfectantSludge -- Congress prohibited ocean dumpingPretreatment of industrial wastes

Non point source pollutionAgricultural runoffUrban runoffAir pollutants deposited by rain

Safe Drinking WaterSurface water

Clean water act helpsGround water

Generally cleanerCommunity water treatment to produce

potable waterCoagulation and flocculationSettlingFiltrationDisinfection

Safe Drinking Water, ctd.EPA has set standards for 87 identified

contaminantsSecondary standards for 15 contaminants

that may affect taste, odor, color, or cause discoloration of teeth

Annual reports required for customers – “right-to-know” about contaminants and health effects

CDC collects data on water-borne disease outbreaks

Regulated ContaminantsDisinfectants -- chlorineDisinfection byproducts -- chloriteInorganic chemicals – metals, asbestos, cyanideOrganic chemicals – herbicides, pesticides,

PCBsMicroorganisms – bacteria, viruses,

cryptosporidiumRadionuclidesTurbidity

Dilemmas in ComplianceNew York City fighting EPA order to filter

its water – cost is too highTrying to protect watershed for reservoirs in

Catskill MountainsCost is a problem in many communitiesDisinfectants may produce harmful

byproductsNew concern – trace amounts of

hormones, pharmaceuticals and household chemicals in many waterways

Shortages of Potable WaterMost water on earth’s surface is salt water or

iceLess than 1 percent is fresh waterWater shortages in many parts of the worldWater shortages in U.S. south and westPolitical disputes