Pós-Graduate Program in Civil Engineering (PPGEC), Technology Center, Federal University of Santa Maria (UFSM), Santa Maria 97105-900, RS, Brazil.
Pós-Graduate Program in Environmental Engineering (PPGEAmb), Technology Center, Federal University of Santa Maria (UFSM), Santa Maria 97105-900, RS, Brazil.
Ecotoxicol Environ Saf. 2021 May;214:112049. doi: 10.1016/j.ecoenv.2021.112049. Epub 2021 Mar 2.
The disposal of untreated sanitary sewage in the soil has several consequences for human health and leads to environmental risks; thus, it is necessary investigating, monitoring and remediating the affected sites. The aims of the current study are to evaluate ecotoxicological effects on Eisenia andrei earthworms exposed to soil subjected to sources of sanitary sewage discharge and to investigate whether prevention values established by the Brazilian legislation for soil quality, associated with the incidence of chemical substances in it, are satisfactory enough to assure the necessary quality for different organisms. Earthworms' behavior, reproduction, acetylcholinesterase activity, catalase, superoxide dismutase and malondialdehyde levels were evaluated. The reproduction and behavior of earthworms exposed to sanitary sewage were adversely affected. Increased superoxide dismutase and catalase activity acted as antioxidant defense mechanism. Significantly increased lipid peroxidation levels and acetylcholinesterase activity inhibition have indicated lipid peroxidation in cell membrane and neurotransmission changes, respectively. Results have confirmed that sanitary sewage induced oxidative stress in earthworms. In addition, based on biochemical data analysis, the integrated biomarker response (IBR) has evidenced different toxicity levels in earthworms between the investigated points. Finally, results have indicated that effluents released into the soil, without proper treatment, lead to contaminant accumulation due to soil saturation and it can hinder different processes and biological development taking place in the soil. In addition, the current study has shown that physical-chemical analyses alone are not enough to assess soil quality, since it is also requires adopting an ecotoxicological approach. Brazilian legislation focused on soil quality must be revised and new guiding values must be proposed.
未经处理的卫生污水在土壤中的排放对人类健康有多种影响，并导致环境风险；因此，有必要调查、监测和修复受影响的地点。本研究的目的是评估暴露于受卫生污水排放源污染的土壤中的赤子爱胜蚓的生态毒理学效应，并研究巴西制定的与土壤中化学物质含量相关的土壤质量预防值是否足以保证不同生物所需的质量。评估了蚯蚓的行为、繁殖、乙酰胆碱酯酶活性、过氧化氢酶、超氧化物歧化酶和丙二醛水平。暴露于卫生污水中的蚯蚓的繁殖和行为受到了不利影响。超氧化物歧化酶和过氧化氢酶活性的增加起到了抗氧化防御机制的作用。脂质过氧化水平的显著增加和乙酰胆碱酯酶活性的抑制分别表明细胞膜的脂质过氧化和神经递质传递的变化。结果证实了卫生污水对蚯蚓造成了氧化应激。此外，基于生化数据分析，整合生物标志物响应（IBR）表明，在所研究的地点，蚯蚓的生物标志物反应存在不同的毒性水平。最后，结果表明，未经适当处理而排放到土壤中的污水会因土壤饱和而导致污染物积累，并可能阻碍土壤中发生的不同过程和生物发育。此外，本研究表明，仅进行理化分析不足以评估土壤质量，因为还需要采用生态毒理学方法。必须修订巴西专注于土壤质量的立法，并提出新的指导值。
