Epidemiology, causality, and public policy

The tension between science & public policy has been increasing as the government seeks scientific advice on more complex issues. Difficult as it is to estimate scientifically the health effects of wide-reaching environmental factors, policymakers need answers to these issues sooner & in more detail than scientists can provide, & often must make decisions before the final word is in. The alternative to formulating policy on the basis of hunches or wizardry is for both policymakers & scientists to become conversant with the subtle strengths & weaknesses of analyses using observational data, so that even when the evidence is not enough to convince many scientists of causality, existing information can be used responsibly. The critical issue of air pollution abatement is presented as an example. 5 Tables, 1 Figure. Modified AA.