Lead levels in bone and hair of rats treated with lead acetate.

The use of hair and bone as media in evaluation of lead exposure was investigated in this study. For 12-16 wk rats were given tap water containing lead acetate in the following concentrations: 41.7 mg Pb/L, 83.3 mg Pb/L, and 166.6 mg Pb/L. The animals were sacrificed every 4 wk and their tibia bones and hair were collected for determination of lead content. In control animals, the lead level amounted to 1.2 micrograms/g (range 0.8-1.3 micrograms/g) and 0.7 microgram/g (range 0.4-2.0 micrograms/g) in bone and hair, respectively. In the treated rats the accumulation of lead in bone and hair occurred in a dose-dependent manner. A positive correlation (r = 0.876) was established between the lead levels in bone and hair of the rats. The regression equation was as follows: microgram Pb/g bone = 0.842 x microgram Pb/g hair + 1.868. After discontinuation of exposure, a significant decrease in the lead content in bone and hair was noticed. About 9 wk after cessation of treatment, the lead content in hair declined to the pre-exposure level, but 64% of the maximal lead concentration did remain in bone. The results of this study indicate that during a continuous exposure the lead level in hair reflects its content in bone. Such phenomena did not occur during the post-exposure period.