Impactos ecotoxicológicos de efluentes líquidos provenientes de atividades hospitalares

Abstract

The increasing pressure on aquatic ecosystems due to human activities has increased scientific interest in assessing the ecotoxicity of effluents from health services. Hospital units are considered relevant sources of environmental contaminants, since they use a wide range of chemicals, including drugs, disinfectants, and cleaning agents, essential for their care routines and sterilization. Thus, the present study aimed to characterize the physicochemical properties and evaluate the ecotoxicological effects of effluents from different sectors of a hospital unit located in the municipality of Francisco Beltrão (PR), which discharges its effluents directly into the sewage collection network without specific prior treatment. The samples were collected at five points representative of hospital operational stages, including areas for initial cleaning (P1), ultrasonic processing (P2), chemical sterilization with sodium hypochlorite (P3), and stages of endoscopic equipment processing, namely enzymatic washing (P4) followed by a 2% glutaraldehyde solution (P5). Hospital effluents showed a high organic load, evidenced by the high values of biochemical and chemical oxygen demand at all evaluated points, whose concentrations reached values up to 14 times higher than those normally reported for effluents, in addition to the presence of antibiotics such as ciprofloxacin, cefazolin, and metronidazole, and elevated pH in P3. The point associated with chemical disinfection (P5) of endoscopic equipment stands out as the most critical because it concentrates the three drugs simultaneously. Ecotoxicological tests showed acute toxicity in Artemia salina (P1 to P5), behavioural escape responses (P1, P4, and P5) and mortality (P3) in Eisenia fetida, toxic changes (P3, P4, and P5) and cytotoxic changes (P2) in Allium cepa, and cytotoxic and proliferation effects in in vitro cellular systems (P1 to P5). The multivariate analyses indicated an association between toxicity, organic load, and the presence of antimicrobials, suggesting a joint action of these factors. The results show that hospital effluents have high complexity and high ecotoxicological potential, reinforcing the need for integrated approaches to the monitoring and improvement of treatment systems, especially those aimed at the removal of emerging contaminants.