Ecotoxicological Risk Assessment of Hospital Wastewater and Management Recommendations
The ecotoxicological risk assessment of hospital effluents is necessary for their management, given their concentrations in pollutants toxic to aquatic organisms, such as disinfectants, detergents, or pharmaceutical residues. To do this, a battery of complementary ecotoxicity tests has been deployed at different sites of the Hospices Civils de Lyon. Monitoring ecotoxicity of effluents during a daily activity showed strong evolution of the latter depending on the activities of the site. Measurement of the ecotoxicity of the particulate fraction of the effluent demonstrated the major contribution of the latter to the total ecotoxicity of the effluent. Parallel to this experimental work, a theoretical study, on all pharmaceuticals consumed in Lyon hospitals, identified to 14 priority medicines to be studied because of their particularly bioaccumulative nature, and their capacity therefore to lead to a significant impact on aquatic organisms and trophic chains. An ecotoxicological risk assessment of these pharmaceuticals was then undertaken, coupling the estimation of their concentration in the receiving medium, and the characterization of their ecotoxicity. This ecotoxicological risk assessment demonstrated the importance of bioaccumulative pharmaceuticals in the overall risk posed by hospital effluents. Based on these results, discussions have been initiated to reduce the risk via different treatments at source and/or pretreatment of these effluents before discharge into the urban sewage network.