Mercury: major issues in environmental health.

摘要: In the past, methylmercury compounds were manufactured as fungicides or appeared unwanted byproducts of chemical industry, but today methylation inorganic mercury in aquatic sediments and soils is predominant if not sole source methylmercury. This form bioaccumulated to a high degree food chains attain its highest concentrations edible tissues long-lived predatory fish living both fresh ocean waters. It well absorbed from diet distributes within few days all body. crosses without hindrance blood-brain placental barriers reach principal target tissue, brain. eliminated chiefly feces after conversion mercury. The biological half-time human about 50 days, there wide individual variation. Adult poisoning characterized by focal damage discrete anatomical areas brain such visual cortex granule layer cerebellum. A latent period weeks months may ensue before appearance signs symptoms poisoning. latter manifest themselves paresthesia, ataxia, constriction fields, hearing loss. prenatal most sensitive stage life cycle Prenatally poisoned infants exhibit range effects severe cerebral palsy subtle developmental delays. Methylmercury believed inhibit those processes specially involved development growth neuronal cell division migration.