EHS 507

Setting the PEL

Old PEL Sig Risk* New PEL L.F. Risk* Data

Arsenic 500 g/m3

148-767 10 g/ m3

2.2-2.9 Epidemiology

Ethylene Oxide

• 50 ppm• 63-109• 1 ppm• 1.2-2.3• Toxicology

*Excess deaths/1000 exposed for 45 yr.

THE MORAL/ETHICAL DIMENSION

•When it comes to setting standards and exposure limits:-–who decides what?–on behalf of whom?–on what basis?

INTERDISCIPLINARY FACTORS IN ENVIRONMENTAL HEALTH ISSUES

• Natural scientists• Life sciences• Physical sciences• Social scientists• Behavioral sciences• Management sciences• Political

A STANDARD AS THE BASIS FOR CONTROLLING EXPOSURE

1 Elimination of the risk factor.2 Technical reduction of

exposure.3 Administrative procedures to

reduce exposure.4 Personal responsibility.

. . . . THE STANDARD AS A ‘YARDSTICK’ AGAINST WHICH TO MEASURE THE EFFECTIVENESS OF

CONTROL.

HIERARCHYOF CONTROLS

REGULATION OF THE ENVIRONMENT IN THE U.S.• Environmental Protection Environmental Protection

Agency (EPA)Agency (EPA) founded in 1970• President Nixon’s charge to

the first EPA Administrator “to “to treat air pollution, water treat air pollution, water pollution and solid wastes as pollution and solid wastes as different forms of a single different forms of a single problem . .”problem . .”

EPA MISSION• Clean air• Clean and safe water• Safe food• Preventing pollution and reducing risk

in communities, homes, etc. and ecosystems

• Better waste management• Reduction of global environmental risks• Expansion of right to know• Sound science• Effective management

SOME KEY ENVIRONMENTAL REGULATORY MILESTONES

Environmental Protection Agency (EPA)Environmental Protection Agency (EPA)• Clean Air Act (1970, amended 1990)• Clean Water Act (1977)• Lead Contamination Control Act (1988)• Food Quality Protection Act (1996)Occupational Safety and Health Occupational Safety and Health

Administration (OSHA)Administration (OSHA)• Occupational Safety and Health Act

(1970)

CONTROL OPTIONS FOR AIR POLLUTION FROM INDUSTRY

• Change process or equipment.

• Reduction in production• Substitution of materials.• Air cleaning technology.• Improve dilution and

dispersal.• Shut down operation!

CONTROL OPTIONS FOR MOBILE EMISSIONS

•Less cars and trucks.

•Cleaner vehicles.•Better fuel

economy•Cleaner fuels.

CONTROL OPTIONS FOR SAFE DRINKING WATER

• Protect groundwater at source:-– reduce agricultural runoff.– careful placement of landfill.– control industrial discharges.

• Water treatment:-– filtration (sand, adsorbers).– softening.– distillation.

ENGINEERING TREATMENT OF MUNICIPAL LIQUID WASTE

(i.e., sewage)• Primary :-

– holding tank to remove suspended solids by settling; floating oils, etc. are skimmed off and passed to anaerobic digester.

• Secondary (biological):-– transformation under aerobic and

anaerobic conditions. • Tertiary:-

– filtration and disinfection.

STANDARDS FOR SOLID WASTE• In the USA, the primary agency

for promulgating and enforcing regulations about solid waste is EPA.

• Solid Waste Disposal Act in 1974; Comprehensive Environmental Response, Compensation and Liability Act (Superfund) in 1980; later amendments.

SOLID WASTE MANAGEMENT• EPA now requires minimization

of production of solid waste by polluters:-– segregation at source.– elimination/substitution of raw

materials.– changing manufacturing

processes.

SOLID WASTE TREATMENT

•A wide range of physical, chemical or biological processes aimed at:-–neutralizing the material (making it safe).

–recovering useful energy or materials.incineration a useful approach,

but need to be careful when burning plastics

FOOD SAFETY• In the USA, several agencies are

responsible for food safety:-– FDA (labeling, food additives, food

processing, etc.)– DoA (inspection and labeling of meat

and eggs, imports, human nutrition aspects of food, etc.)

as well as EPA (use of pesticides, etc.)• Microbiological hazards a major part,

both in processing and in domestic use.

KEY INTERVENTIONS (Food Code, US

Department of HHS, FDA, 1999) • Demonstration of knowledge

• Employee health controls• Controlling hands as a vehicle of

contamination• Time/temperature controls• Consumer advisory• Address risk factors documented

by CDC

CONTROL MEASURES FOR INDOOR AIR POLLUTANTS

Pollutant Control

Radon progeny, tobacco smoke, aerosols, etc.

Ventilation

Organic materials, lead, asbestos, tobacco, etc.

Eliminate source

Aerosols, vapors Air cleaners

Organic substances, tobacco, etc.

Behavioral adjustment

STANDARDS FOR OCCUPATIONAL HAZARDS

• In the USA, the primary agency for promulgating and enforcing workplace standards is the Occupational Health and Safety Administration (OSHA).

• Occupational Safety and Health Act in 1970, amended in 1974, 1978, 1982 and 1984.

• Also influential: the American Conference of Governmental Industrial Hygienists (ACGIH).

TECHNICAL CONTROL OPTIONS FOR THE WORKPLACE

• Change process or equipment.• Reduction in production.• Substitution of materials.• General exhaust ventilation.• Local exhaust ventilation.• Personal protective equipment

– respirators– hearing protectors– eye protectors, etc.}the last

resort!!

RADIATION SAFETY• The players:-

– International Commission on Radiological Protection (ICRP)

– NCRP– Federal Radiation

Council (FRC)

NCRP RECOMMENDATIONS (1987) FOR TOTAL RADIATION DOSE

TYPES OF EXPOSURE LIMIT VALUE

Occupational 50 mSv (annual)

Public 1 mSv (annual)

Embryo-Fetus 5 mSv

a heavy smoker may be getting

close to this

a uranium miner may be getting

close to this

FACTORS INFLUENCING RADIATION

PROTECTION•Distance•Time•Shielding•Sanitation

stay as far away as possible

keep exposure time as short as possible

do all that is necessary to keep radioactive materials

out of the body

interpose dense material (e.g., lead,

concrete, water, etc.) between

source and subject

STORAGE OF WASTE RADIOACTIVE MATERIALS

(e.g., SPENT NUCLEAR FUEL)

•For long-lived radioactive material (e.g., Pu239):-–Treatment and concentration.

–Encapsulation.– Interment at sea or underground.