Increased frequencies of sister chromatid exchanges and micronuclei in "in vitro" lymphocyte cultures treated with the fungicides thiram and ziram.

The two fungicides analysed in this paper, Thiram (TH) and Ziram (ZI) are among the most common residues found in fruit and vegetables sold in Italy. These compounds were tested in "in vitro" lymphocyte cultures, from 16 individuals, at different concentrations (Thiram 5 x 10(-8) M; 5 x 10(-7) M; 5 x 10(-6) M and Ziram 1 x 10(-7) M; 1 x 10(-6) M; 1 x 10(-5) M) in order to ascertain if they are able to modify sister chromatid exchange and/or micronuclei frequencies. Both fungicides produced a significant increase in SCE and Micronuclei frequencies. The two highest doses of TH and ZI were found to be cytotoxic for most of the individuals and were not included in the statistical analysis. With regard to the Proliferation Rate Index (i.e. the number of first, second, third or more mitoses), no difference was found between controls and treated cultures.