Lead absorption in cows: Biological indicators of ambient lead exposure

In order to determine actual lead exposure from residual amounts of lead in the environmental soil following the introduction of effective engineering emission controls in a lead smeltery, the absorption of lead in cows grazing in the vicinity was investigated. Four groups of cows were examined: two groups of cows exposed to different amvient lead concentration. Compared with two normal groups of cows. The results demonstrated normalization of ALAD, EP and Pb-B after the technical sanitation. In spite of normalization biological indicators ALAD and Pb-B determined four years after the technical sanitation showed increased lead absorption in comparison with the results of the control group. This indirectly indicates lead contamination of the environment from residual amounts of lead in the soil. The biologically active lead deposit from past exposure could be an additional factor in the prolonged effect of lead in the body.