KWR Watercycle Research Institute, Groningenhaven 7, 3433 PE Nieuwegein, The Netherlands.
KWR Watercycle Research Institute, Groningenhaven 7, 3433 PE Nieuwegein, The Netherlands.
Environ Int. 2018 Sep;118:293-303. doi: 10.1016/j.envint.2018.05.006. Epub 2018 Jun 14.
Toxicological risk assessment of contaminants of emerging concern (CEC) in (sources of) drinking water is required to identify potential health risks and prioritize chemicals for abatement or monitoring. In such assessments, concentrations of chemicals in drinking water or sources are compared to either (i) health-based (statutory) drinking water guideline values, (ii) provisional guideline values based on recent toxicity data in absence of drinking water guidelines, or (iii) generic drinking water target values in absence of toxicity data. Here, we performed a toxicological risk assessment for 163 CEC that were selected as relevant for drinking water. This relevance was based on their presence in drinking water and/or groundwater and surface water sources in downstream parts of the Rhine and Meuse, in combination with concentration levels and physicochemical properties. Statutory and provisional drinking water guideline values could be derived from publically available toxicological information for 142 of the CEC. Based on measured concentrations it was concluded that the majority of substances do not occur in concentrations which individually pose an appreciable human health risk. A health concern could however not be excluded for vinylchloride, trichloroethene, bromodichloromethane, aniline, phenol, 2-chlorobenzenamine, mevinphos, 1,4-dioxane, and nitrolotriacetic acid. For part of the selected substances, toxicological risk assessment for drinking water could not be performed since either toxicity data (hazard) or drinking water concentrations (exposure) were lacking. In absence of toxicity data, the Threshold of Toxicological Concern (TTC) approach can be applied for screening level risk assessment. The toxicological information on the selected substances was used to evaluate whether drinking water target values based on existing TTC levels are sufficiently protective for drinking water relevant CEC. Generic drinking water target levels of 37 μg/L for Cramer class I substances and 4 μg/L for Cramer class III substances in drinking water were derived based on these CEC. These levels are in line with previously reported generic drinking water target levels based on original TTC values and are shown to be protective for health effects of the majority of contaminants of emerging concern evaluated in the present study. Since the human health impact of many chemicals appearing in the water cycle has been studied insufficiently, generic drinking water target levels are useful for early warning and prioritization of CEC with unknown toxicity in drinking water and its sources for future monitoring.
需要对饮用水（源）中新兴关注污染物（CEC）的毒理学风险进行评估，以识别潜在的健康风险，并优先对化学品进行减排或监测。在这种评估中，饮用水或水源中的化学物质浓度与以下各项进行比较：(i)基于健康（法定）的饮用水指导值，(ii)在没有饮用水指导值的情况下，基于近期毒性数据的临时指导值，或 (iii)在没有毒性数据的情况下，通用饮用水目标值。在这里，我们对 163 种被选为与饮用水相关的 CEC 进行了毒理学风险评估。这种相关性是基于它们在莱茵河和默兹河下游的饮用水和/或地下水和地表水水源中的存在，以及浓度水平和物理化学特性。对于 142 种 CEC，可以从公开的毒理学信息中得出法定和临时饮用水指导值。根据实测浓度，结论是大多数物质的浓度不会单独对人类健康造成明显风险。然而，氯乙烯、三氯乙烯、溴二氯甲烷、苯胺、苯酚、2-氯苯甲胺、甲拌磷、1,4-二恶烷和氮三乙酸的健康风险仍不能排除。对于部分选定的物质，由于缺乏毒性数据（危害）或饮用水浓度（暴露），无法进行饮用水毒理学风险评估。在没有毒性数据的情况下，可以应用毒理学关注阈值（TTC）方法进行筛选水平风险评估。所选物质的毒理学信息用于评估基于现有 TTC 水平的饮用水相关 CEC 的饮用水目标值是否具有足够的保护作用。根据这些 CEC，饮用水中 I 类克雷默物质的通用饮用水目标值为 37μg/L，III 类克雷默物质的通用饮用水目标值为 4μg/L。这些水平与之前基于原始 TTC 值报告的通用饮用水目标水平一致，并且被证明对本研究评估的大多数新兴关注污染物的健康影响具有保护作用。由于许多出现在水环中的化学物质的人体健康影响研究不足，通用饮用水目标值对于早期预警和优先考虑饮用水及其水源中未知毒性的 CEC 进行未来监测非常有用。
