Genotoxicity of water samples from an area of the Pampean region (Argentina) impacted by agricultural and livestock activities

The aim of this study was to assess the genotoxic potential of surface waters located in a rural area in the north east of Buenos Aires province (Argentina) using the Allium cepa test. Water samples were collected at four sites located in a drainage channel and two sites on the Burgos stream that receives water from the channel, taking into account the sowing and harvesting months and rainfall periods. Analytical determinations revealed high total concentrations of Cd, Cu, Pb, and Zn (maximum values: 0.030, 0.252, 0.176, and 0.960 mg L−1, respectively), and concentrations of glyphosate and its metabolite aminomethylphosphonic acid (AMPA), with maximum values of 13.6 and 9.75 μg L−1, respectively. Statistically positive correlations were observed between the total metal concentrations and precipitation. No cytotoxicity (mitotic index MI) was observed in A. cepa. However, several water samples showed significant increases in micronucleus (MN) frequencies with respect to the controls. No correlations were observed between MN and the abiotic variables or precipitation. These results showed a state of deterioration in the water quality at the rural area studied in Buenos Aires province, and heavy metal contamination may contribute to the genotoxic activity. A. cepa was shown to be a useful tool for the detection of genotoxicity in water samples from areas with agricultural and livestock activities.