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.摘要 接受血液透析治疗的患者人数持续增长，由此产生的透析废液排量也随之攀升。此类废液含有高浓度盐类、氮化物与有机物，此外还可能掺杂药物与微生物。在市政管理体系中，血液透析废液通过管道接入污水管网，最终排放至地表水体。利用种子开展的毒理学测试兼具操作简便、耗材成本低廉的优势，且结果可靠；但该方法无法确定引发毒性的具体污染物种类，仅能反映混合污染物的整体毒性。基于此，本研究旨在评估巴西南里奥格兰德州南部地区最大医院产生的血液透析废液的植物毒性（phytotoxicity）、细胞毒性（cytotoxicity）与遗传毒性（genotoxicity）。本研究采用的样本为在五台透析设备的不同班次中，于每次透析疗程的起始、中期与结束阶段采集的混合样本。测试样本包括纯废液、稀释废液、透析液配制用水、纯透析液、稀释透析液以及对照组。植物毒性测试采用绿长（Verde Comprido）黄瓜种子，以及雷吉娜德维拉奥（Regina de Verão）与拉博德加洛（Rabo-de-Galo）生菜种子；细胞与遗传毒性分析则采用贝亚佩里弗姆（Baia Periforme）洋葱种子。研究观察到，纯血液透析废液与纯透析液对所有受试种子均产生毒性作用。尽管稀释废液未对生菜与黄瓜造成植物毒性，但细胞与遗传毒性测试结果显示，洋葱细胞的有丝分裂指数出现下降，且出现染色体畸变现象，表明该废液在细胞与遗传层面存在毒性。基于上述结果可得出结论：此类废液不得直接排放至水体资源，未经预处理也不得用于灌溉回用。