MERCURY CONTENT IN RAT TEETH AFTER ADMINISTRATION OF ORGANIC AND INORGANIC MERCURY

Rat molars are indicators of exposure concentration and target organ c ontent in chronic mercury vapor exposure. We wished to study the accum ulation and persistence of organic and inorganic mercury in rat teeth and the effect of selenium on mercury retention. Male Wistar rats rece ived either inorganic or organic mercury (with or without addition of selenite), selenite only, or no mercury or selenite (controls) in the drinking water for 4 weeks. Group A was killed after exposure. Group B was killed 20 weeks later. The mercury content was measured by cold-v apor atomic absorption spectrophotometry. The mercury content in the m olars in group B was 66% and 77% less than in group A after inorganic and organic exposure, respectively. In the incisors the corresponding reductions were 90% and 97%. Selenite had limited effect on mercury re tention in group A and none in group B. We suggest that rat molars and , by inference, human deciduous teeth may serve as indicators of organ ic and inorganic mercury exposure.