Evaluation of phytotoxic, cytotoxic, and genotoxic potential of hemodialysis effluent

Abstract

The number of patients undergoing hemodialysis treatment increases and, consequently, the volume of effluent generated. This effluent presents high concentration of salts, nitrogen, and organic matter; furthermore, it may contain drugs and microorganisms. At the municipal level, hemodialysis effluent is piped to sewage networks and discharged to surface water. Toxicological tests using seeds provide reliable answers, with simplicity and low cost of procedures and materials; however, it does not allow to identify the agent that causes toxicity, but the toxicity of the set of contaminants. In this sense, the objective of this work was to evaluate phytotoxicity, cytotoxicity, and genotoxicity of the hemodialysis effluent generated in the largest hospital of the southern region of Rio Grande do Sul. Composite samples collected at the beginning, middle and end of each session on five machines and different shifts were used. Pure and diluted effluent, water for the composition of the dialysate, pure and diluted dialysate and control were tested. The phytotoxicity tests were performed with seeds of Verde Comprido cucumber, and Regina de Verão and Rabo-de-Galo lettuce. For cytogenotoxicity analyses, Baia Periforme onion seeds were used. It was observed that the pure hemodialysis effluent and dialysate had a toxic effect on all analyzed seeds. Although the diluted effluent did not cause phytotoxicity in lettuce and cucumber, cytogenotoxicity tests showed a decrease in mitotic index and appearance of chromosomal aberrations in onion cells, indicating toxicity at a cellular and genetic level. These results allow to conclude that this effluent cannot be directly dumped into water resources, nor can it be reused in irrigation without prior treatment.