Knowledge about human behavioral teratology/toxicology must necessarily be limited by the methods that can ethically be used. Research in the field is an enterprise calling for tolerance for uncertainty if not chaos. Among the main points of this paper are: (a) Kaufman's criticisms of research on low blood-lead level (BLL) and children's IQ are generally valid and apply to virtually all human n...

Two categories of reference limits can be discerned in biological monitoring: The first category identifies individuals who have been exposed to a toxic agent at work, and is based on the distribution of the concentration of the agent or its metabolite in the population that has not been exposed to the agent at work. The second category, for which the term biological action level (BAL) is propo...

BACKGROUND There is a need to evaluate complex interaction effects on human health, such as those induced by mixtures of environmental contaminants. The usual approach is to formulate an additive statistical model and check for departures using product terms between the variables of interest. In this paper, we present an approach to search for interaction effects among several variables using b...