Evaluation of genotoxic and cytotoxic properties of pesticides employed inItalian agricultural practices

In a program coordinated by the Italian Ministry of Works, we tested in vit ro four pesticides widely employed in a developed agricultural region of ce ntral Italy. The four commercial agents were chosen on the basis of their d iffusion in agricultural practice, knowledge of their active principle(s), and scant availability of data concerning their toxic and genotoxic activit y. The agents were Cirtoxin, Decis, Tramat Combi (TC), and Lasso Micromix ( LM). All substances were tested in three in vitro systems: Chinese hamster ovary (CHO) cells, a metabolically competent hamster cell line (Chinese ham ster epithelial liver; CHEL), and root tips of Vicia faba (VF). The cytotox ic and genotoxic end points challenged were micronuclei and root tip length (RTL) in VF and mitotic index (MI), proliferation index (PI), cell surviva l (CS), cell growth (CG), cell cycle length (CCL), sister chromatid exchang es, chromosomal aberrations, and single-cell gel electrophoresis, or comet assay, in CHEL and CHO cells. Tested doses ranged from the field dose up to 200 x the field dose to take into account accumulation effects. On the who le, tested agents appear to induce genotoxic damage only at subtoxic or tox ic doses, indicating a low clastogenic risk. MI, PI, CS, CG, RTL, and CCL a ppear to be the less sensitive end points, showing no effects in the presen ce of a clear positive response in some or all of the other tests. Using cy togenetic tests, we obtained positive results for TC and LM treatments in C HO but not in CHEL cells. These data could be accounted for by postulating a detoxifying activity exerted by this cell line. However, cytogenetic end points appear to be more sensitive than those referring to cytotoxicity, (C ) 2000 Academic Press.