Influence of town wastewaters and agricultural activities on water genotoxicity during different river level regimes

Abstract

Water, being of critical importance for the survival of life on the planet, requires our permanent care and attention. There is a growing concern about the genotoxicity of complex environmental mixtures present in surface waters, due to the risk of genetic damage and cancer, both in aquatic organisms and humans. The present study focuses on exploring the status of water pollution in areas with combined industrial and agricultural activities in order to estimate the magnitude of toxicity and genotoxicity using the Allium test. We collected samples from the Sava and Danube rivers, upstream and downstream of Šabac (Sava River) and Smederevo (Danube River). In both rivers sampling was done in periods of low and high water levels. Levels of toxicity were low in both rivers, although the presence of organic pollution was seen from higher root mean length in all sample groups than in negative controls. The highest values of genotoxicity at locations upstream of both Šabac and Smederevo were obtained in samples collected in a period of high water level, but only the upstream sample from the Sava River had reached a significant level of genotoxicity. This can be explained as a consequence of intensive agricultural activities. Our results indicate that communal town and industrial wastewaters influence river water quality more significantly during low level regimes, while high water levels increase the risk of exposure to chemicals used in agriculture.