Objectives: A study was conducted to evaluate the genotoxic impregnation consecutive to a 1-day open-field spraying of pesticides.
Methods: From 14 farmers (five smokers and nine non-smokers), three urine samples were collected at the end of the spraying season: the morning (S1) of the day of spraying, the evening (S2) and the morning (S3) of the following day. A fourth sample (S0) was obtained before the pesticide-handling period. Mutagenicity of urine extracts was evaluated with the Ames test, using strains TA97a, TA98, TA100 and TA102, with and without S9 mix.
Results: The ratio of induced vs spontaneous revertants (induction ratio) was > or =2 in five farmers (including three smokers), with only one strain responding in each. Applying the SALM software proposed by Kim and Margolin in combination with the ANOVA-Dunnett test on crude data (number of revertants), urine extracts were found to be mutagenic on at least one Salmonella strain in 57% and 96% of non-smokers and smokers, respectively. The proportion of mutagenic responses tended to increase from S1 to S3 (not statistically significant) in non-smokers only. Finally, there were no relationships between the relative changes in the number of revertants (adjusted for urine concentration) and any exposure parameters available: area sprayed, number of tanks prepared and time free of exposure to any pesticide.
Conclusions: The lack of significant relationships between urine mutagenicity and exposure data argues against a direct role of the pesticides sprayed, on this impregnation. This result should be considered with caution since the number of farmers involved may limit the significance of the study.