ECOTOXICITY OF WASTEWATER FROM HEALTH CARE FACILITIES

Wastewater from health care facilities receives a wide range of chemicals particularly pharmaceuticals, disinfectants, heavy metals, contrast agents and radionuclides. Many of these substances are not completely removed in the wastewater treatment process and they get to the surface water and groundwater where may pose a risk to the environment and human health. Attention in connection with wastewater from health care facilities should be also paid to microbial contamination and the occurrence of resistant strains of microorganisms. Ecotoxicity assessment should be an important criterion for monitoring quality of wastewater from health care facilities and environmental and health risk assessment. Ecotoxicological tests as opposed to chemical analysis can also affect synergic or antagonistic effect of substances contained in wastewater. In the presented work, the ecotoxity assessment of treated wastewater discharged from wastewater treatment plants of three health care facilities in the Czech Republic was performed. Ecotoxicological tests specified in the legislation of the Czech Republic for evaluation of the ecotoxicity as hazardous characteristic of waste was used in this work for ecotoxicity assessment of wastewater. Tested organisms were representatives of phytoplankton (Desmodesmus subspicatus), zooplankton (Daphnia magna), higher plants (Sinapis alba) and fish (Poecilia reticulata). The aim of the presented work was also an assessment of the suitability of selected organisms for ecotoxicity testing of wastewater, because currently in the world there are not defined unified methodologies to evaluate the ecotoxicity of wastewater. In ecotoxicological tests with wastewater from health care facilities, the most sensitive organisms were daphnids (Daphnia magna) and algae (Desmodesmus subspicatus). It is necessary to evolve a unified biotest battery in order to ecotoxicity can partially or completely replace the expensive and time-consuming chemical analysis in wastewater quality monitoring in future. The biotest battery should include tested organisms of all trophic levels.