Setting the PEL

1
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.
2
THE MORAL/ETHICAL DIMENSION

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

3
INTERDISCIPLINARY FACTORS IN ENVIRONMENTAL HEALTH
ISSUES

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

4
A STANDARD AS THE BASIS FOR CONTROLLING EXPOSURE

• Elimination of the risk factor.
• Technical reduction of exposure.
• Administrative procedures to reduce exposure.
• Personal responsibility.
• . . . . THE STANDARD AS A YARDSTICK AGAINST
  WHICH TO MEASURE THE EFFECTIVENESS OF CONTROL.

HIERARCHY OF CONTROLS
5
REGULATION OF THE ENVIRONMENT IN THE U.S.

• Environmental Protection Agency (EPA) founded in
  1970
• President Nixons charge to the first EPA
  Administrator to treat air pollution, water
  pollution and solid wastes as different forms of
  a single problem . .

6
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

7
SOME KEY ENVIRONMENTAL REGULATORY MILESTONES

• 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 Administration
  (OSHA)
• Occupational Safety and Health Act (1970)

8
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!

9
CONTROL OPTIONS FOR MOBILE EMISSIONS

• Less cars and trucks.
• Cleaner vehicles.
• Better fuel economy
• Cleaner fuels.

10
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.

11
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.

12
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.

13
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.

14
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
15
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.

16
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

17
CONTROL MEASURES FOR INDOOR AIR POLLUTANTS
18
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).

19
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!!
20
RADIATION SAFETY

• The players-
• International Commission on Radiological
  Protection (ICRP)
• NCRP
• Federal Radiation Council (FRC)

21
NCRP RECOMMENDATIONS (1987) FOR TOTAL RADIATION
DOSE
a heavy smoker may be getting close to this
a uranium miner may be getting close to this
22
FACTORS INFLUENCING RADIATION PROTECTION
stay as far away as possible

• Distance
• Time
• Shielding
• Sanitation

keep exposure time as short as possible
interpose dense material (e.g., lead, concrete,
water, etc.) between source and subject
do all that is necessary to keep radioactive
materials out of the body
23
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.