HERBICIDE-INDUCED DNA-DAMAGE IN HUMAN-LYMPHOCYTES EVALUATED BY THE SINGLE-CELL GEL-ELECTROPHORESIS (SCGE) ASSAY

The genotoxicity of the herbicides, alachlor, atrazine, maleic hydrazi de, paraquat and trifluralin has been evaluated in the single-cell gel electrophoresis (SCGE) assay by using human peripheral blood lymphocy tes. All treatments were conducted with and without the presence of an external bioactivation source (S9 mix). The results indicate that all the herbicides tested are able to give positive results by increasing the comet tail length, which would confirm both the genotoxicity of t he herbicides and the sensitivity of the assay in front of these chemi cals. Alachlor and atrazine give similar results in treatments with an d without S9, while when the S9 mix was not used paraquat and triflura lin genotoxicity was higher. On the other hand, although maleic hydraz ide genotoxicity was higher when S9 mix was used at normal pH (7.4), o ur data show that its genotoxicity depends largely on the pH solution, increasing as the pH decreased.