RISK-FACTORS, CAUSALITY, AND POLICY INITIATIVES - THE CASE OF ALUMINUM AND MENTAL IMPAIRMENT

The question addressed is when can the evidence concerning a health is sue be regarded as adequate to implement policy initiatives. The appro ach is illustrated by comparing evidence about the effects of cigarett e smoking with evidence for the aluminum (Al) hypothesis (that Al cont ributes to mental impairment and especially to Alzheimer's Disease). T he criteria for evaluating the evidence are based on the consistency a nd strength of the association between a putative risk factor and the relevant outcome variable, the Likelihood that the relative risk repre sents a causal relationship, whether possible mechanisms are available , the number of persons affected, and the costs of modifying the risk factor. (C) 1998 Elsevier Science Inc.