Nieuwenhuijsen Mark J, Grellier James, Smith Rachel, Iszatt Nina, Bennett James, Best Nicky, Toledano Mireille
Centre for Research in Environmental Epidemiology (CREAL), Parc de Recerca Biomèdica de Barcelona-PRBB (Office 183.05), , C. Doctor Aiguader, 88, 08003 Barcelona, Spain.
Philos Trans A Math Phys Eng Sci. 2009 Oct 13;367(1904):4043-76. doi: 10.1098/rsta.2009.0116.
This paper summarizes the epidemiological evidence for adverse health effects associated with disinfection by-products (DBPs) in drinking water and describes the potential mechanism of action. There appears to be good epidemiological evidence for a relationship between exposure to DBPs, as measured by trihalomethanes (THMs), in drinking water and bladder cancer, but the evidence for other cancers including colorectal cancer is inconclusive and inconsistent. There appears to be some evidence for an association between exposure to DBPs, specifically THMs, and little for gestational age/intrauterine growth retardation and, to a lesser extent, pre-term delivery, but evidence for relationships with other outcomes such as low birth weight, stillbirth, congenital anomalies and semen quality is inconclusive and inconsistent. Major limitations in exposure assessment, small sample sizes and potential biases may account for the inconclusive and inconsistent results in epidemiological studies. Moreover, most studies have focused on total THMs as the exposure metric, whereas other DBPs appear to be more toxic than the THMs, albeit generally occurring at lower levels in the water. The mechanisms through which DBPs may cause adverse health effects including cancer and adverse reproductive effects have not been well investigated. Several mechanisms have been suggested, including genotoxicity, oxidative stress, disruption of folate metabolism, disruption of the synthesis and/or secretion of placental syncytiotrophoblast-derived chorionic gonadotropin and lowering of testosterone levels, but further work is required in this area.
本文总结了与饮用水中消毒副产物（DBPs）相关的不良健康影响的流行病学证据，并描述了潜在的作用机制。对于饮用水中以三卤甲烷（THMs）衡量的DBPs暴露与膀胱癌之间的关系，似乎有充分的流行病学证据，但对于包括结直肠癌在内的其他癌症的证据尚无定论且不一致。对于DBPs暴露，特别是THMs暴露与胎龄/宫内生长迟缓之间的关联似乎有一些证据，而对于早产的关联证据较少，在较小程度上，对于低出生体重、死产、先天性异常和精液质量等其他结局的关系证据尚无定论且不一致。暴露评估中的主要局限性、小样本量和潜在偏差可能是流行病学研究结果尚无定论且不一致的原因。此外，大多数研究将总THMs作为暴露指标，而其他DBPs似乎比THMs毒性更大，尽管在水中的含量通常较低。DBPs可能导致包括癌症和不良生殖影响在内的不良健康影响的机制尚未得到充分研究。已经提出了几种机制，包括遗传毒性、氧化应激、叶酸代谢紊乱、胎盘合体滋养层细胞衍生的绒毛膜促性腺激素合成和/或分泌的破坏以及睾酮水平降低，但该领域还需要进一步的研究。
