Abstract：
We characterized concentrations of trihalomethanes (THMs), a measure of disinfection byproducts (DBPs), in tap water samples collected from households with utility-supplied water in two rural counties in Appalachian Virginia, and assessed associations with pH, free chlorine, and metal ions which can impact THM formation. Free chlorine concentrations in all samples (n = 27 homes) complied with EPA drinking water guidelines, though 7% (n = 2) of first draw samples and 11% (n = 3) of 5-min flushed-tap water samples exceeded the US Safe Drinking Water Act (SDWA) maximum contaminant level (MCL) for THM (80 ppb). Regression analyses showed that free chlorine and pH were positively associated with the formation of THM levels above SDWA MCLs (OR = 1.04, p = 0.97 and OR = 1.74, p = 0.79, respectively), while temperature was negatively associated (OR = 0.78, p = 0.38). Of the eight utilities serving study households, samples from water served by three different utilities exceeded the EPA MCL for THM. Overall, these findings do not indicate substantial exposures to DBPs for rural households with utility-supplied water in this region of southwest Virginia. However, given the observed variability in THM concentrations between and across utilities, and established adverse health impacts associated with chronic and acute DBP exposure, more research on DBPs in rural Central Appalachia is warranted.
摘要：
我们表征了三卤甲烷(THMs)的浓度，消毒副产物(DBPs)的量度，在阿巴拉契亚维吉尼亚州的两个农村县，从拥有公用事业供水的家庭收集的自来水样本中，并评估了与pH值的关系，游离氯,和可以影响THM形成的金属离子。所有样品（n=27个家庭）中的游离氯浓度符合EPA饮用水指南，尽管7％（n=2）的首次抽取样品和11％（n=3）的5分钟冲洗自来水样品超过了美国安全饮用水法（SDWA）的THM最大污染物水平（MCL）（80ppb）。回归分析表明，游离氯和pH与高于SDWAMCL的THM水平的形成呈正相关（分别为OR=1.04，p=0.97和OR=1.74，p=0.79），而温度呈负相关(OR=0.78,p=0.38)。在为研究家庭服务的八家公用事业公司中，来自三个不同公用事业公司的水的样品超过了THM的EPAMCL。总的来说,这些发现并未表明，在弗吉尼亚州西南部的该地区，拥有公用事业供水的农村家庭对DBPs的大量暴露。然而,考虑到公用事业之间和跨公用事业的THM浓度的变化，并确定与慢性和急性DBP暴露相关的不良健康影响，有必要对阿巴拉契亚中部农村地区的DBPs进行更多研究。
