Neurobehavioral assessment of Mohawk Indians for subclinical indications of methyl mercury neurotoxicity.

Abstract

A total of 200 male and 200 adult female Mohawk Indians were examined by means of performance tests as part of a total health evaluation of participants in a medical field survey on the St. Regis Reserve. Age-corrected performance test scores were studied in relation to blood, urinary, and hair methyl mercury (MeHg) levels, and local fish consumption. Males were found to eat more fish than females and had relatively higher MeHg levels than females. Blood and hair MeHg levels were significantly correlated with local fish consumption for both sexes. Biological indicators of MeHg absorption suggested low exposure levels but did not correlate significantly with performance test scores. These findings indicate that the time of examination, St. Regis residents were exposed to almost "background" levels of MeHg and did not exhibit either subclinical or clinical manifestations of MeHg neurotoxicity.