MCS: the status of population-based research.

MCS has been studied predominantly in clinical and occupational settings. Since the mid-1990's, a few investigators have examined dimensions of this controversial syndrome in the general population. In this discussion, the role of epidemiology in learning about MCS is presented. Some of the challenges of population-based research on MCS are discussed. Specific studies are presented with regard to study population, case definition, exposure and case classification methods, interpretation, and conclusions.