SISTER-CHROMATID EXCHANGES IN VICIA-FABA INDUCED BY ARSENIC-CONTAMINATED DRINKING-WATER FROM ZIMAPAN, HIDALGO, MEXICO

Sister chromatid exchanges (SCE) in Vicia faba root tips were used to examine well water containing high levels of arsenic. The increased am ount of arsenic was contained in well water from different towns of Zi mapan, Hidalgo, Mexico. Treatments of 3 h were applied followed by the differential staining technique of Tempelaar et al. (Mutation Res. 10 3 (1982) 321-326). Concentrations of arsenic from 0.267 up to 1.070 mg /l were determined by colorimetry in the polluted samples used for thi s study. These values were above the permissible limit of 0.05 mg/l in drinking water. In all cases, except one in which the As concentratio n was 0.021, the arsenic-contaminated water produced significant incre ases of SCE compared with the control (p < 0.001) and a concentration- response relationship was observed. The SCE potency factor of 33 per m g/l of arsenic was calculated as the slope of a common regression line , pooling data previously obtained in the Comarca Lagunera and the res ults observed in Zimapan. (C) 1997 Elsevier Science B.V.