Dependence of apparent blood lead half-life on the length of previous lead exposure in humans.

The expected relationship between the apparent half-life of blood lead (PbB) and the length of previous exposure is compared with the observed relationship in a group of workers on strike from a primary smelter where they had been employed for from a few months to ten years. Within this group, the apparent PbB half-life was positively correlated both with pre-strike PbB and with length of exposure to lead. It is likely that the dependence of apparent half-life on pre-strike PbB is primarily a reflection of interindividual differences in lead kinetics in these men. The direct dependence of apparent half-life on duration of lead exposure is consistent with published data from former lead workers and from human subjects experimentally exposed to lead.