Comparative study of genotoxic effects in workers exposed to inorganic lead and low dose irradiation using micronucleus test

Abstract

This paper presents a case-control study of micronuclei score evaluation as cytogenetic test in male workers exposed to inorganic lead from a non-ferrous metallurgical plant, Romania. Literature data on genotoxic effects of this heavy metal are still matter of discussions. We have compared micronuclei frequency measured from the lymphocytes of both inorganic lead-exposed and radiation-exposed workers as well as their respective matched controls. The study consisted of 60 subjects divided into three groups: lead exposed workers, workers exposed to ionizing radiation and controls. Exposure to inorganic lead was assessed either by determination of lead concentration in the workplace air or by biotoxicological analyses (blood lead level, urine lead level, urine δ-aminolevulinic acid). The results of our investigation showed an increased micronuclei mean score in lead-exposed workers compared to control group (6.0±2.328‰ vs. 2.7±0.978‰, p<0.001). We found that lead produces chromosomal damage comparable to that induced by ionizing radiation (micronuclei mean score 5.55±1.877‰ in subjects exposed to X rays). In conclusion, we propose the use of the micronucleus assay as a screening test for occupationally lead-exposed workers displaying repeated occupational poisoning and pathological outcome.