THE KINETICS OF INTRAVENOUSLY ADMINISTERED METHYL MERCURY IN MAN

We describe a compartmental pharmacokinetic model for methyl mercury a nd its metabolite mercuric mercury in humans. A tracer dose of Hg-203- labeled methyl mercury was administered iv to seven healthy young adul t male volunteers. Blood samples w ere obtained periodically and urine and feces were collected throughout the 70 days of the study. The blo od contained predominantly methyl mercury, while the excreta contained principally inorganic mercury. The behavior of both methyl mercury an d inorganic mercury in the body was modeled with the simplest compartm ental model which fit the data. This five-compartment model shows that inorganic mercury accumulates in the body and at longer times is the predominant form of mercury present. The biological half-life of methy l mercury in the body is 44 days and 1.6% of the body burden is lost e ach day by both metabolism and excretion. This rate of loss is 60% gre ater than that currently accepted (1.0% per day). Thus, the risk assoc iated with dietary methyl mercury may have been overestimated. (C) 199 1 Academic Press, Inc.