Molecular markers of exposure to cadmium and nickel among alkaline battery workers

Abstract

T he goal of the study wasto evaluate the usefulness of metallothionein mRNA, anti-5- hydroxymethyl-2'-deoxyuridine antibodies titres (anti-HMdU Ab), and 8-hydroxydeoxyguanosine (8OHdG) in urine as markers of the biologically active dose after exposure to airborne cadmium and nickel in human studies. Exposed persons (n = 38) were chosen from workers involved in the production and assembly, chemistry, and maintenance departments of a nickel-cadmium battery factory in Poland. Controls (n = 52) were chosen from administration personnel at the factory. Biological samples from workers were collected twice: once in the summer, after a month of vacation, and again in the winter, after 3 months of regular working activity within the plant. Controls were recruited during the second phase of the study. When exposure groups were defined on the basis of ambient air cadmium measurements, we found a two-fold increase in mean metallothionein mRNA values in the highest exposure group (air cadmium above 1000 g m-3) and a positive correlation of metallothionein mRNA with blood cadmium levels (r = 0 46, p < 0 008). Future studies can be designed to investigate further the interand intra-subject component of the variability and the possibility of the existence of M T gene polymorphisms, determining different responses and susceptibilities to cadmium exposure. We did not find any difference in the mean values of anti-HMdU Ab titres and 8OHdG in urine in any of the exposure groups analysed. Nickel exposure appeared to have greater impact on anti-HMdU Ab titres than cadmium.