EJMS

Abstract

Background: Methylmercury exists in soil, air, water and in fishes especially large ones like tuna, swordfish, tilefish, marlin, shark, and king mackerel. It has become one of the “most hazardous environmental pollutants reaching levels of potential toxicity especially in our aquatic ecosystems. Objectives: The aim of the study was to assess the health hazards of exposure to the methyl mercury chloride especially its cytotoxicity and genotoxicity. Methods: Blood samples were collected from thirty healthy adult subjects and four lymphocyte cultures were done for each subject. Methyl mercury chloride was added 24 hours later in concentration of O, 50, 500 and 5000 µg/ L respectively for each case. The metaphase chromosomes were analyzed using two techniques, Giemsa staining and GTG banding. One hundred metaphase were analyzed for each lymphocyte culture with a total of 3.000 metaphase for each concentration. Results: Methyl mercury chloride induced different forms of numerical (aneuploidy, hyperploidy and chromatid endoreduplication) and structural chromosomal aberrations (breaks, satellite associations, double minutes formation and chromosome rearrangements) in a concentration related manner. The mitotic index of the cultured lymphocytes showed a proportionate decrease with increase in the concentration of the methyl mercury indicating the cytotoxicity of methyl mercury chloride. Conclusions: Methyl mercury chloride is geno- and cytotoxic. It can induce different forms of numerical and structural chromosomal aberrations and cause decrease in the mitotic index of the exposed cells.