Oxidative stress in Cyprinus carpio induced by hospital wastewater in Mexico

The very wide range of activities performed in hospitals (care, diagnosis, hygiene, maintenance, research) require the use of a large variety of potentially ecotoxic substances such as surfactants, metals, disinfectants and pharmaceuticals. This study aimed to determine oxidative stress in the common carp Cyprinus carpio induced by hospital wastewater (HWW) in Mexico. The median lethal concentration (LC50) and subsequently the lowest observed adverse effect level were determined. Carp were exposed to the latter value (0.5 %) for 24, 48, 72 and 96 h, and the following biomarkers were evaluated in gill, brain, liver and blood: hydroperoxide content (HPC), malondialdehyde (MDA) content, protein carbonyl content (PCC) and activity of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT). Significant increases in HPC, MDA content and PCC were observed in exposed specimens, particularly in gill, liver and brain. SOD and CAT activity also increased in liver and brain. In conclusion, this particular HWW induces oxidative stress on C. carpio, this damage being most evident in gill, liver and brain.