“A thing is safe if its risks are judged to be acceptable” Wm. Lowrance, 1976

Elements of the RA-RM Paradigm Risk Assessment Risk Management Risk Characterization Risk Communication Technical Information- Gathering, Measurement Value/Policy Judgment, Risk Acceptability Summarizing Technical Detail for Deciders and Overseers Taking Information to Interested Publics

“The Dose Makes the Poison” We all have body burdens of lead, DDT, PCB, etc. The effects, if any, are difficult to determine (compare cholera, AIDS) Many innocuous substances can, if consumed in excessive amounts, cause injury or death (water, table salt) So, how much is too much?

Dose-Response Curves (“QRA”) Higher Doses Response (e.g., death) Threshold

A B

Where Do Dose-Response Curves Come From? X X X X X X

Some Nasty Problems of QRA Have we chosen the right end points? Should we test for multi-generational effects? Is the end point dose-dependent rather than, e.g., time-dependent? Are there especially sensitive species or populations? Are there synergistic/antagonistic effects with other substances, mixtures? How conservative should our assumptions be? How should we deal with impacts on species, natural communities, ecosystems?

Uncertainty Provides an Opportunity for Advocacy

Some Risk Management Frameworks Cost-benefit Feasibility analysis Risk-risk Precautionary Principle “Protect the most vulnerable with an adequate margin of safety”

Tort Framework (Carroll Towing—an “expected value” criterion) [Gravity of Harm] * [Probability] vs. Cost of avoidance [avoidance may be probabilistic]

“Risk assessments are like captured spies—if you torture them enough, they’ll tell you anything you want to hear” William Ruckelshaus, twice Administrator of EPA

A toxicological “Devil’s Dictionary” “Junk Science” Any study which undercuts the position I am advocating “Sound Science” It sounds like science, and it supports my position

Some more jargon Congeners (e.g., PCBs) TEQs (Toxic Equivalency factors) (e.g., dioxins, furans)