“…This aspect reinforces the concept that there must be other substances or chemicals in the water samples that were not detected a priori but even so exert weighty toxicological effects. Several reports showed that C. elegans was sensitive to different substances such as pesticides, heavy metals and toxins (Höss et al, 2013;Jiang et al, 2016;Lewis et al, 2013;Negga et al, 2011;Ruan et al, 2009;Yunhui et al, 2009). So it is possible that C. elegans toxicity could be explained by pollutants derived from the anthropogenic activities developed in the area (like agriculture, livestock and recreations).…”