National Institute for Public Health and the Environment, P.O. Box 1, 3720, BA, Bilthoven, the Netherlands.
National Institute for Public Health and the Environment, P.O. Box 1, 3720, BA, Bilthoven, the Netherlands.
Sci Total Environ. 2024 Dec 1;954:176572. doi: 10.1016/j.scitotenv.2024.176572. Epub 2024 Sep 28.
Free cyanide is considered to be the most toxic form of cyanides to aquatic life. Due to its broad range of uses and subsequent potential widespread emissions to surface water, the environmental effects of free cyanide have been extensively researched. Regulatory bodies have proposed water quality standards for free cyanide, but these are regularly debated and implementation has been inconsistent due to monitoring challenges. The aim of the present study was therefore to derive new environmental quality standards (EQS) for free cyanide according to the Water Framework Directive (WFD). Ecotoxicity data from previous derivations and an additional literature search were gathered and individually (re) evaluated on reliability. The pooled acute ecotoxicity dataset consisted of reliable results for 35 species, distributed over 8 taxonomic groups. The pooled chronic ecotoxicity dataset consisted of results for 13 species, distributed over 7 taxonomic groups. WFD criteria for deriving a species sensitivity distribution (SSD) were met, if censored data points were included. Using the R-package ETX 3.0, an SSD including censored data was constructed and acute and chronic HC values of 17 and 0.66 μg/L, respectively, were derived. Comparisons were made with alternative SSDs constructed by transforming or discarding the censored data. Applying a default assessment factor (AF) of 10 to the HC from the acute SSD resulted in a MAC-EQS of 1.7 μg CN/L for freshwater and marine water. Careful consideration was given to addressing the uncertainty around the chronic HC value for the selection of an AF of 3, resulting in an AA-EQS of 0.22 μg CN/L for freshwater and 0.044 μg CN/L for marine water by applying an additional AF of 5. It is concluded that the current environmental quality standards for free cyanide are the first to be derived according to the WFD guidance, using only reliable data and including censored values.
游离氰化物被认为是对水生生物毒性最大的氰化物形式。由于其广泛的用途和随后可能向地表水广泛排放，游离氰化物的环境影响已得到广泛研究。监管机构已经为游离氰化物提出了水质标准，但由于监测挑战，这些标准经常受到争议，并且实施情况不一致。因此，本研究旨在根据《水框架指令》（WFD）为游离氰化物制定新的环境质量标准（EQS）。从前一推导和额外文献搜索中收集了毒理学数据，并对其可靠性进行了单独（重新）评估。汇总的急性生态毒性数据集由 35 个物种的可靠结果组成，分布在 8 个分类群中。汇总的慢性生态毒性数据集由 13 个物种的结果组成，分布在 7 个分类群中。如果包含截尾数据点，则满足推导物种敏感性分布（SSD）的 WFD 标准。使用 R 包 ETX 3.0，构建了包含截尾数据的 SSD，并分别推导出 17 和 0.66 μg/L 的急性和慢性 HC 值。与通过转换或丢弃截尾数据构建的替代 SSD 进行了比较。将急性 SSD 中的 HC 值应用默认评估因子（AF）10 后，淡水和海水的 MAC-EQS 分别为 1.7 μg CN/L 和 1.7 μg CN/L。在选择 AF 3 时，仔细考虑了慢性 HC 值的不确定性，通过应用额外的 AF 5，为淡水和海水分别得出 AA-EQS 为 0.22 μg CN/L 和 0.044 μg CN/L。综上所述，本研究是第一个根据 WFD 指南，仅使用可靠数据并包含截尾值为游离氰化物制定环境质量标准的研究。
