This study evaluated transplacental mercury transfer by measuring Hg in blood samples of mothers and newborns (umbilical cord)
IntroductionStudies on mercury (Hg) in the Amazon region in the 1980s and 1990s emphasized the extent of mercury pollution in gold-mining areas, due mainly to source emission, dispersion mechanisms, and accumulation in geological materials (soils, sediments, and water) and in the aquatic biota, mainly fish. Several studies have also focused on identifying populations (especially riverside dwellers) potentially exposed to organic mercury compounds through consumption of foods containing high Hg levels 1,2,3,4,5,6 . These studies concentrated on mercury pollution in gold-mining areas, but without approaching clinical aspects of exposure to Hg compounds 5,7,8,9 .The first study on clinical signs and symptoms emphasized prospectors, gold shop workers, and riverside communities in the Tapajós Basin, with the first reports of suspected cases of mercury poisoning between 1986 and 1991 10 . The study assessed Hg levels in blood and urine samples and included motor coordination tests. Despite high Hg levels in the samples, no clinically confirmed signs and symptoms of mercury poisoning were identified in these individuals. This apparent paradox has been attributed to the high prevalence of tropical diseases in the Amazon region that can mask the classical signs and symptoms of Hg poisoning. However, studies are needed that integrate information on the health conditions of these communities, including the Cad. Saúde Pública, Rio de Janeiro,