Methyl mercury uptake and associations with the induction of chromosomal aberrations in Chinese hamster ovary (CHO) cells

In order to evaluate possible health effects of environmental exposure of humans towards methyl mercury species, relevant exposure experiments using methyl mercury chloride in aqueous solution and Chinese hamster ovary (CHO) cells were performed. The solution was monitored for the presence of monomethyl, dimethyl and elemental mercury by several analytical techniques including chromatographic as well as atomic absorption and mass spectrometric methods. Methyl mercury induces structural chromosomal aberrations (CA) and sister chromatid exchanges (SCE) in CHO cells. At a concentration of methyl mercury in the culture medium of 1.0 x 10(-6) M where the frequencies of CA and SCE are significantly elevated, the intracellular concentration was 1.99 x 10(-16) mol/cell. Possible biochemical processes leading to the cytogenetic effects are discussed together with toxicological consequences, when humans (e.g. workers at waste deposits) are exposed to environmental concentrations of methyl mercury.