Exposure to
mercury can cause serious multiorgan damage affecting the central nervous system, kidneys, liver, lungs, spleen, bone marrow, and skin. At the end of the summer of 1999, the accidental leakage of 4 liters of
mercury from a container into the waterway canals resulted in mass exposure to elemental
mercury among the residents of a building block of a residential area of the city of Shiraz, in the south of Iran. One hundred and eleven individuals who experienced exposure to elemental
mercury were investigated. Twenty-four-hour measurement of the urine
mercury level-revealed a toxic level of more than 20 microg/L in 6 children and 3 adults (including a pregnant woman). Despite normal physical and laboratory (CBC, renal and liver function tests, and urinalysis) findings,
dimercaprol was prescribed. One month later during the course of the follow-up the urine
mercury level in 6 patients, including the pregnant woman from the same family, was found to be again at a toxic level. The pregnant mother from the same family aborted her fetus; however, due to the lack of equipment for measuring the serum
mercury level, it was not possible to confirm the relation between the
mercury toxicity and the abortion. This family had kept
mercury in their kitchen against health workers' instructions. The attractive physical and chemical properties of
mercury could explain the continuity of exposure and
poisoning in these 6 cases. It is concluded that prophylactic
therapy in the presence of toxic levels of
mercury, despite the presence of an
asymptomatic state in exposed residents, is effective in preventing the development of signs and symptoms, though instruction of high-risk cases is the best way to combat it.