1. Part 1e Part 1e INTERVENTIONS

2. PRACTICAL ISSUES Policies Standards Administration measures Technical measures

3. AN ENVIRONMENTAL HEALTH POLICY... the outcome of political behavior by which individuals or groups of individuals, often representing parties with competing interests, strive to influence an end point which takes the form of environmental health-related legislation and regulation.

4. AN ENVIRONMENTAL HEALTH STANDARD “.... A MEASURABLE REFERENCE POINT, WITHIN A POLICY FRAMEWORK, CONSISTING OF SPECIFIC CRITERIA AND GUIDELINES, BY WHICH THE DESIRED OBJECTIVE CAN BE QUANTIFIED AND MEASURED” (POLICY SPECIALIST AT U.K. HEALTH AND SAFETY EXECUTIVE, 1997)

5. INGREDIENTS OF A STANDARD AN EXPOSURE LIMIT –Criterion: the metric of exposure most appropriate to the outcome. –Measurement: a means to measure the exposure according to that metric. –Strategy: by which to assess exposures for populations over long periods of time. -- and usually -- SPECIFICATION of how exposure limit is to be met

6. EXAMPLES OF EXPOSURE LIMITS An air concentration of a chemical below which, over a specified period of time (e.g., lifetime), “no” harm will come. A concentration of an organism in water or food below which the chance of infection in humans will be small. The number of hours in one day that a truck driver may work.

7. PHILOSOPHY BEHIND EXPOSURE LIMITS (e.g., ENVIRONMENTAL) An exposure level at which:- –the chance of an adverse outcome is less than a specified amount (e.g., less than 1:10 6 over a lifetime). –the days of loss of life expectancy (LLE) fall below a certain number. –etc.

8. PHILOSOPHY BEHIND EXPOSURE LIMITS (e.g., OCCUPATIONAL) Occupational Exposure Limits (OELs) for chemical exposures [in the U.S. termed permissible exposure limits (PELs)]:- “The Secretary (of Labor) … shall set the standard which most adequately assures, to the extent feasible, … that no employee will suffer material impairment of health or functional capacity … for the period of his working life [45 years]”

9. EHS 507 How OSHA Sets Health Standards Lowest Feasible Risk Excess Deaths 1000 Exposed “Significant Risk” Cumulative Exposure (45 yr) Exposure-Response Curve (Slope derived from Epid or Tox) New PELOld PEL Feasibility PEL = “Permissible Exposure Limit”

10. EXAMPLE: ENVIRONMENTAL STANDARD FOR RISK TO THE PUBLIC ASSOCIATED WITH LOW- LEVEL EXPOSURE TO ASBESTOS FIBERS 1010 -1 10 -3 10 -5 10 -1 10 -7 Lifetime risk of lung cancer or mesothelioma Respirable asbestos fiber concentration (fibers/cm 3 ) Actual data from occupational epidemiology Range of interest

11. ACCEPTABLE RISK IN STANDARDS SETTING? None at all? –e.g., the largely ideological Russian OELs. Some risk? –e.g., OELs in most countries. Virtually no risk? –e.g., US ambient exposure standards. e.g., air, water, other risk factors, etc.

12. DIFFERENCES IN WHAT IS ACCEPTABLE RISK Occupational (higher) versus ambient (lower). Voluntary (higher) versus involuntary (lower). Very-unpleasant outcomes (lower) versus less-unpleasant outcomes (higher). Cultural (e.g., life expectancy varies between countries).

13. EHS 507 ACGIH/OSHA 76,000 µg/day EPA70 µg/day Food for thought: why do exposure standards differ so greatly? Exposure Limits for Epichlorohydrin

14. EHS 507 Setting the PEL  Old PEL  Sig Risk*  New PEL  L.F. Risk*  Data Arsenic  500  g/m 3  148-767  10  g/ m 3  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.