Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
Department of Engineering Management and Systems Engineering, The George Washington University, Washington, DC 20052, USA.
J Environ Sci (China). 2017 Aug;58:191-207. doi: 10.1016/j.jes.2017.05.043. Epub 2017 Jun 10.
Natural and anthropogenic factors can alter bromide concentrations in drinking water sources. Increasing source water bromide concentrations increases the formation and alters the speciation of disinfection byproducts (DBPs) formed during drinking water treatment. Brominated DBPs are more toxic than their chlorinated analogs, and thus have a greater impact on human health. However, DBPs are regulated based on the mass sum of DBPs within a given class (e.g., trihalomethanes and haloacetic acids), not based on species-specific risk or extent of bromine incorporation. The regulated surrogate measures are intended to protect against not only the species they directly represent, but also against unregulated DBPs that are not routinely measured. Surrogates that do not incorporate effects of increasing bromide may not adequately capture human health risk associated with drinking water when source water bromide is elevated. The present study analyzes trihalomethanes (THMs), measured as TTHM, with varying source water bromide concentrations, and assesses its correlation with brominated THM, TTHM risk and species-specific THM concentrations and associated risk. Alternative potential surrogates are evaluated to assess their ability to capture THM risk under different source water bromide concentration conditions. The results of the present study indicate that TTHM does not adequately capture risk of the regulated species when source water bromide concentrations are elevated, and thus would also likely be an inadequate surrogate for many unregulated brominated species. Alternative surrogate measures, including THM and the bromodichloromethane concentration, are more robust surrogates for species-specific THM risk at varying source water bromide concentrations.
自然和人为因素会改变饮用水源中的溴化物浓度。原水溴化物浓度的增加会增加饮用水处理过程中消毒副产物（DBP）的形成，并改变其形态。溴化 DBP 比氯化类似物毒性更大，因此对人类健康的影响更大。然而，DBP 的监管是基于给定类别内 DBP 的质量总和（例如，三卤甲烷和卤乙酸），而不是基于特定物种的风险或溴化程度。受监管的替代指标旨在不仅防止直接代表的物种，而且防止未受监管的 DBP，这些 DBP 通常未被测量。不考虑溴化物增加影响的替代指标在原水溴化物升高时，可能无法充分捕捉与饮用水相关的人类健康风险。本研究分析了三卤甲烷（THM），以总三卤甲烷（TTHM）的形式表示，具有不同的原水溴化物浓度，并评估其与溴化 THM、TTHM 风险以及特定物种的 THM 浓度和相关风险的相关性。评估了替代潜在替代指标，以评估它们在不同原水溴化物浓度条件下捕捉 THM 风险的能力。本研究的结果表明，当原水溴化物浓度升高时，TTHM 不能充分捕捉受监管物种的风险，因此对于许多未受监管的溴化物种，TTHM 也可能是一种不充分的替代指标。替代替代指标，包括 THM 和二溴氯甲烷浓度，是在不同原水溴化物浓度下更可靠的特定物种 THM 风险替代指标。
