Toxic Metal Half-Lives, Organ Distribution, and Normal Rates of Excretion

Toxic Metal Half-Lives, Organ Distribution, and Normal Rates of Excretion 

The half-lives of toxic metals vary over an enormous range and the value for a given toxic metal depends upon the site at which it is deposited. Thus the half-life of mercury in the whole blood of men following exposure to mercury vapor was found to be 3.1 days for a fast phase and 18 days for a slow phase. In this same study the half-life for the mercury in the urine was found to be 40 days (Barregard et al. 1992). In a similar study of a more severe human exposure a half-life of 45 days was estimated (Bluhm et al. 1992). In this latter group of workers the administration of DMSA produced a threefold increase in the amount of mercury excreted in the urine, while the administration of A-acetyl-D,L-penicillamine produced a twofold increase. The half-life of mercury in the human brain may be much longer than this (Cavanagh 1988). The half-life of elements which deposit in the bone, such as lead, can be of the order of many years (Rabinowitz et al. 1976). 

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