Department of Occupational and Environmental Health, School of Public Health, Guangxi Medical University, Nanning 530021, PR China.
Key Laboratory of the Public Health Safety, Ministry of Education, Department of Environmental Health, School of Public Health, Fudan University, Shanghai 200032, PR China.
Sci Total Environ. 2021 May 20;770:145277. doi: 10.1016/j.scitotenv.2021.145277. Epub 2021 Jan 21.
Halobenzoquinones (HBQs) are emerging unregulated drinking water disinfection byproducts (DBPs) that are more toxic than regulated DBPs. This study aimed to determine the distribution and formation of HBQs in drinking water from water treatment plants in China, compare their chronic cytotoxicity and their induction of chromosomal damage in Chinese hamster ovary cells, and analyze the correlation of HBQ toxicity with their physicochemical parameters. Two HBQs, 2,6-dichloro-1,4-benzoquinone (2,6-DCBQ) and 2,6-dibromo-1,4-benzoquinone (2,6-DBBQ), were detected in finished water and tap water in China. The concentrations were in the ranges of <2.6-19.70 ng/L for 2,6-DCBQ and <0.38-1.8 ng/L for 2,6-DBBQ. Chemical oxygen demand and residual chlorine were positively correlated with HBQ formation. The HBQ concentration was lower in a drinking water treatment plant using chlorine dioxide. High Ca in tap water decreased the HBQ level. The rank order of HBQ by cytotoxicity was 2-chloro-1,4-benzoquinone > 2,3-diiodo-1,4-benzoquinone > 2,6-diiodo-1,4-benzoquinone > 2,6-dibromo-1,4-benzoquinone > 2,5-dibromo-1,4-benzoquinone > 2,5-dichloro-1,4-benzoquinone > 2,6-dichloro-1,4-benzoquinone > tetrachloro-1,4-benzoquinone > 2,3,6-trichloro-1,4-benzoquinone, and for their genotoxicity, 2,5-dichloro-1,4-benzoquinone > 2,6-dichloro-1,4-benzoquinone > 2,3-diiodo-1,4-benzoquinone > 2,6-diiodo-1,4-benzoquinone > tetrachloro-1,4-benzoquinone > 2,5-dibromo-1,4-benzoquinone > 2,6-dibromo-1,4-benzoquinone > 2,3,6-trichloro-1,4-benzoquinone. The cytotoxicity of six dihalo-HBQs was negatively correlated with the octanol-water partition coefficient (r = -0.971, P < 0.05), molar refractivity (r = -0.956, P < 0.05), energy of the highest occupied molecular orbital (E) (r = -0.943, P < 0.05), and polar surface area (r = -0.829, P < 0.05). The genotoxicity of these three pairs of dihalo-HBQ isomers followed the same order as their E values. This study reveals the occurrence and formation of HBQs in drinking water in China and systematically evaluates the chromosomal damage caused by nine HBQs in mammalian cells.
卤代苯醌（HBQs）是新兴的不受管制的饮用水消毒副产物（DBPs），其毒性比受管制的 DBPs 更强。本研究旨在确定中国水处理厂饮用水中 HBQs 的分布和形成情况，比较它们对中国仓鼠卵巢细胞的慢性细胞毒性及其诱导的染色体损伤，并分析 HBQ 毒性与其理化参数的相关性。在中国，自来水中检测到两种 HBQ，2,6-二氯-1,4-苯醌（2,6-DCBQ）和 2,6-二溴-1,4-苯醌（2,6-DBBQ）。浓度范围分别为<2.6-19.70ng/L 的 2,6-DCBQ 和<0.38-1.8ng/L 的 2,6-DBBQ。化学需氧量和余氯与 HBQ 形成呈正相关。使用二氧化氯的饮用水处理厂的 HBQ 浓度较低。自来水中高钙会降低 HBQ 水平。按细胞毒性排序，HBQ 为 2-氯-1,4-苯醌>2,3-二碘-1,4-苯醌>2,6-二碘-1,4-苯醌>2,6-二溴-1,4-苯醌>2,5-二溴-1,4-苯醌>2,5-二氯-1,4-苯醌>2,6-二氯-1,4-苯醌>四氯-1,4-苯醌>2,3,6-三氯-1,4-苯醌，其致突变性为 2,5-二氯-1,4-苯醌>2,6-二氯-1,4-苯醌>2,3-二碘-1,4-苯醌>2,6-二碘-1,4-苯醌>四氯-1,4-苯醌>2,5-二溴-1,4-苯醌>2,6-二溴-1,4-苯醌>2,3,6-三氯-1,4-苯醌。六种二卤代 HBQ 的细胞毒性与辛醇-水分配系数（r=-0.971，P<0.05）、摩尔折射率（r=-0.956，P<0.05）、最高占据分子轨道能量（E）（r=-0.943，P<0.05）和极性表面积（r=-0.829，P<0.05）呈负相关。这三对二卤代 HBQ 异构体的致突变性与其 E 值相同。本研究揭示了中国饮用水中 HBQs 的发生和形成情况，并系统评估了 9 种 HBQ 对哺乳动物细胞染色体损伤的情况。
