Occupational exposure to lead and induction of genetic damage.

To investigate whether occupational exposure to lead is genotoxic, we evaluated data from 103 lead-exposed workers and 78 matched controls. These data correspond to three different sampling periods, and we measured genetic damage as increases in the frequency of binucleated cells with micronuclei (BNMN) in peripheral blood lymphocytes. The levels of exposure were determined according to the lead levels in blood. Clearly significant increases in BNMN were observed in the exposed groups when compared to the control group. In addition, for the overall population (n = 181), we observed a clear relationship between lead levels in blood and BNMN (r = 0.497; p < 0.001). When we examined four exposure levels--very low exposure (< 1.20 microM/L), low exposure (1.20-1.91 microM/L), high exposure (1.92-2.88 microM/L), and very high exposure (> 2.88 microM/L)--we found significant differences in the genetic damage induction. We conclude that exposure to levels of lead higher than 1.20 microM/L may pose an increase in genetic risk. In addition, our data show that blood lead level is a good indicator of genetic damage induction.