Cyprus International Institute for Environmental and Public Health in association with Harvard School of Public Health, Cyprus University of Technology, Limassol, Cyprus.
Cyprus International Institute for Environmental and Public Health in association with Harvard School of Public Health, Cyprus University of Technology, Limassol, Cyprus; Harvard-Cyprus Program, Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA.
Sci Total Environ. 2015 Feb 15;506-507:26-35. doi: 10.1016/j.scitotenv.2014.10.071. Epub 2014 Nov 14.
Gradually-changing shocks associated with potable water quality deficiencies are anticipated for urban drinking-water distribution systems (UDWDS). The impact of structural UDWDS features such as, the number of pipe leaking incidences on the formation of water trihalomethanes (THM) at the geocoded household level has never been studied before. The objectives were to: (i) characterize the distribution of water THM concentrations in households from two district-metered areas (DMAs) with contrasting UDWDS characteristics sampled in two seasons (summer and winter), and (ii) assess the within- and between-household, spatial variability of water THM accounting for UDWDS characteristics (household distance from chlorination tank and service pipe leaking incidences). A total of 383 tap water samples were collected from 193 households located in two DMAs within the UDWDS of Nicosia city, Cyprus, and analyzed for the four THM species. The higher intraclass correlation coefficient (ICC) values for water tribromomethane (TBM) (0.75) followed by trichloromethane (0.42) suggested that the two DMAs differed with respect to these analytes. On the other hand, the low ICC values for total THM levels between the two DMAs suggested a large variance between households. The effect of households nested under each DMA remained significant (p<0.05) for TBM (not for the rest of the THM species) in the multivariate mixed-effect models, even after inclusion of pipe network characteristics. Our results could find use by water utilities in overcoming techno-economic difficulties associated with the large spatiotemporal variability of THM, while accounting for the influence of UDWDS features at points of water use.
与饮用水水质缺陷相关的逐渐变化的冲击预计将出现在城市饮用水分配系统 (UDWDS) 中。以前从未研究过结构 UDWDS 特征（例如，泄漏事件的数量）对在地理编码家庭层面形成水三卤甲烷 (THM) 的影响。目的是：(i) 描述在两个季节（夏季和冬季）采样的具有对比 UDWDS 特征的两个分区计量区域 (DMA) 中家庭的水 THM 浓度分布，以及 (ii) 评估家庭内和家庭间、空间变异性水 THM 占 UDWDS 特征（家庭距离氯化罐和服务管泄漏事件）的比例。总共从塞浦路斯尼科西亚市 UDWDS 内的两个 DMA 中的 193 户家庭中收集了 383 个自来水样本，并对四种 THM 物质进行了分析。水三溴甲烷 (TBM) 的较高类内相关系数 (ICC) 值（0.75）其次是三氯甲烷 (0.42) 表明这两个 DMA 对此类分析物存在差异。另一方面，两个 DMA 之间总 THM 水平的低 ICC 值表明家庭之间存在很大的差异。即使在包括管网特征后，在多变量混合效应模型中，DMA 下嵌套的家庭对 TBM 的影响仍然是显著的（p<0.05）（而其余的 THM 物种则不是）。我们的研究结果可以帮助水务公司克服与 THM 的大时空变异性相关的技术经济困难，同时考虑到用水点处 UDWDS 特征的影响。
