Cytogenetic effect of thiabendazole and diphenylammine on cultured human lymphocytes: sister chromatid exchanges and cell cycle delay.

The two fungicides analysed in this paper, Thiabendazole (TBZ) and Diphenylammine (DPA), are among the pesticides found in higher concentration in fruits and vegetables sold in Tuscany. These compounds were tested in "in vitro" lymphocyte cultures at different concentrations and using 3 protocols; protocol 1: the cultures were treated with the fungicides for 48 h; protocols 2 and 3: the cultures were treated with fungicides for 4 h in the presence or absence of the metabolic activator S9 mix. Both fungicides produced a slight increase in the SCE frequency in the 48 h treatment, at the higher non-toxic concentrations tested, but not when exposed for only 4 h, with or without S9 mix. As far as concerns the Proliferation Rate Index (i.e. the number of first, second and third mitoses), Thiabendazole also produced a significant decrease in the replication rate of the treated cultures, while Diphenylammine did not produce any effect.