An Assessment of the Epidemiological Data on Mercury. H. Daniel Roth, Roth Associates, Inc., 6115 Executive Boulevard, Rockville, MD 20852; and Lihan Yan and Yuanzhang Li, Representing Lignite Research Council, 1016 East Owens Avenue, Suite 200, Bismarck, ND 58502
Based on a review of the literature we have identified 176 epidemiological health effects studies on mercury. Of these, 63 were dropped from consideration because they were unpublished or were not peered-reviewed. We screened the remaining 113 studies based on criteria such as: the sample of the study population was of adequate size, the study reported exposure levels, and the study considered important confounding variables. This led us to reject an additional 93 studies leaving only 20 studies that pass minimal acceptable criteria. Of these latter studies nine dealt with neurological and motor retardation effects, six with general morbidity and mortality, two with reproductive effects, and three with other effects. With regard to study findings, three reported a positive association between mercury and adverse health effects, six reported a negative association, and 11 mixed results. Of the three positive studies two were on general morbidity and mortality effects and one was on other effects. But even these results must be viewed with skepticism because of the statistical analyses in these studies were incomplete or flawed.