Study on water quality criteria, ecological risk and adverse outcome pathway of lindane in freshwater environment

In order to evaluate the ecological risk of lindane in freshwater bodies of China, the short-term and long-term freshwater quality criteria values were derived according to the method of Technical Guideline for Deriving Water Quality Criteria for Freshwater Organisms (HJ 831-2022). The derived short-term and long-term freshwater quality criteria values were 6.15 and 0.12 μg/L, respectively. According to the water quality criteria, the ecological risk of lindane in major freshwater bodies of China was assessed and the results showed that the ecological risk of lindane was at high risk level in Taihu Lake and the Minjiang River of Yangtze River basin, the Yellow River, the Haihe River and the Daliao River estuary. At present, the toxic effect endpoints of ecological risk assessment are still the general toxic effects (MATC, EC₁₀, EC₂₀, NOEC, LOEC, EC₅₀, LC₅₀, etc.), while the adverse outcome pathway (AOP) can qualitatively and quantitatively analyze the causal relation between the pollutants and their toxic effects from the levels of genes, cells, tissues and organs, which can provide a scientific basis for future refined ecological risk assessment. Thus, based on the results of the bibliometric analysis on the toxicity of lindane to freshwater organisms, three adverse outcome pathways of liver injury, reproductive injury and nerve injury were constructed according to the guidelines of the Organization for Economic Co-operation and Development (OECD).