Lecture 4 - Policy, Standards Flashcards
Pros and Cons of Epi and Tox studies for risk assessment
Risk Assessment: use human data whenever possible, use surrogate species only when scientific evidence only when appropriate
pros of tox: understand exposure mechanisms, more flexible design
cons of tox: not done in a humnan, really high doses
pros of epi: use methods to look at humans, good stat power
cons of epi; inferences
Standards Setting Considerations and establishing exposure limits
use dose-outcome information to develop of limit of exposure
acknowldedgement of uncertainty
application of safety factors
moral /ethical dimension
Establishing exposure limits: calculate reference dose, find threshold or NOAEL. apply necessary safety factor
Limits of the US approach
precautionary principle, exposures to mixtures complicate issue, non-monotonic dose-response relationships, ability to detect or predict sensitive low-dose effects
how to better define toxic endpoints
Hormesis
j-shaped curve, a toxic agent may be beneficial at low doses
Other problems with Risk Assessmetn
not meant to inform policy makers, uncertainty and variable are handled inconsistently, default assumptions are highly controversial, panel decisions lack transparency
Difference between law and policy
law: created by legislation, funded by executive office, interpreted by judiciary
regulation: detailed policy on implementation of a law, developed and enforced by executive branch
The need for government intervention
voluntary efforts in unregulated market don;t succeed,
government policing powers: promulgate law ans regulations to protect health: licensing, permitting, enforcement, eminent domain
Major Regulatory agencies
EPA, OSHA, MSHA, DOT, FDA, USDA, CPSC, DOI
also CDC: which has ATSDR, National Center for Environmental Health, NIOSH, NISH
OSH Act
2 means of protection: general duty clause (free from recognized hazards), adherence to specific standards,
many workplaces are not fully compliant with OSHA rules, . also the standards need to change (no standard for ergonomics yet its 30% of workers comp claims)
Exposure Limits (environmental and occupational)
exposure beneath the limit for certain time period will produce no harm.
environmental: chance of an adverse outcome is less than a specified amount, days of loss of life expectancy (LLE) is below threshold
occupational: chemical exposures. levels to which nearly all workers may be exposed day after day without adverse effect. identification with reasonable certainty at which there is no indication of injury
differences in acceptable risk
occ exposure is higher than env exposure, voluntary vs involuntary, degrees of effects, cultural,
Standards for Occupational Hazards
OSHA sets occupational exposure limits OELs in the form permissible exposure limits (PELs) which are LEGALLY enforceable
ACGIH also sets threshold limit values TLVs, which are NOT legally enforceable
Why do people like the ACGIH standards?
derived without consideration of policy or regulation. do not take into account technical feasibility
ACGIH is used worldwide, OSHA just used in the states
OSHA’s burden
evidence the old standard/limit has significant health risks,
evidence that new limit will significantly reduce those risks (burden of proof is on OSHA).
technologic and economic feasibility
What are the 2 categories of OSHA standards?
performance (specify air concentration only), hard to enforce, flexible
design (specify how standard is to be met, procedure oriented), easy to enforce, inflexible
