RELATIONSHIP BETWEEN GENOTOXIC DAMAGE AND ARSENIC BLOOD CONCENTRATIONS IN INDIVIDUALS RESIDING IN AN ARSENIC CONTAMINATED AREA IN MORELOS, MEXICO

Arsenic (As) contaminated drinking water is a well-known problem that still affects millions of people worldwide. Therefore, biomonitoring studies of human populations exposed to arsenic via drinking water along with the search for new biomarkers become important. Huautla, Morelos, Mexico, is a mining district where 780 000 tons of toxic wastes have been discharged at 500 m from Huautla town, where the main contaminants are Pb and As and still, there is no information about their effect on the human population health. Therefore, the aims of this study were: A) To examine As concentration in drinking water and in whole blood samples from the individuals residing in Huautla, Morelos, B) To evaluate DNA damage levels in whole blood lymphocytes from the exposed individuals and C) To evaluate if there is a correlation between DNA damage and total As blood levels from the exposed individuals. Our results demonstrate that drinking water from Huautla, Morelos, is contaminated with As (0.240 +/- 0.008 mu g/ml) exceeding the national (0.025 mu g/ml) and international standards (0.010 mu g/ml). Total As levels in whole blood samples from the exposed individuals corroborate this exposure (60 +/- 9 mu g/l). As stimulated positively the lymphocyte cell cycle and induced DNA breaks and chromosome aberrations (CA), which were positively and significantly correlated with As concentrations in whole blood samples. Among the types of CA analyzed, terminal deletions registered the highest determination coefficient (R-2 = 0.70). We provide evidence that supports the use of total As blood concentration as an internal biomarker of exposure in human populations. A fact that might be of particular interest in subjects with kidney related conditions, in which the normalization of total As/gr creatinine in urine may not reflect accurately the exposure level to this metalloid.