Institute of Environmental Science and Engineering, National University of Science and Technology, H-12, Islamabad, Pakistan.
Ecotoxicol Environ Saf. 2013 May;91:25-31. doi: 10.1016/j.ecoenv.2013.01.008. Epub 2013 Mar 1.
This study aims at monitoring and risk assessment of trihalomethanes (THMs) such as chloroform, bromodichloromethane, dibromochloromethane and bromoform, in the drinking water supplies of Rawalpindi and Islamabad. THMs were monitored at twenty locations in these twin cities using solid phase micro extraction-gas chromatography (SPME-GC). Total concentration of THMs was ranged between 21 and 373μg/L, whereas both cities had an average total THMs concentration of 142 and 260μg/L, respectively. Chloroform was found as one the major contributor to the THMs concentration (>85%). The occurrence of THMs followed the given order: chloroform, bromodichloromethane>dibromochloromethane>bromoform. Lifetime cancer risk assessment of THMs was carried out using prediction models via different exposure routes (ingestion, inhalation and dermal). An average lifetime cancer risk was found to be 0.74×10(-4) and 1.24×10(-4) for Rawalpindi and Islamabad, respectively. The number of expected cancer cases per year could reach two cases for each city. Hazard index values were found below unity for both the cities implying that there would be no considerable non-cancer risk. Oral ingestion was found to be one of the main routes of exposure for both types of risk which was followed by inhalation and dermal routes.
本研究旨在监测和评估拉瓦尔品第和伊斯兰堡的饮用水中三卤甲烷（THMs）的含量，如氯仿、溴二氯甲烷、二溴氯甲烷和溴仿。在这两个双子城市的 20 个地点使用固相微萃取-气相色谱法（SPME-GC）监测 THMs。THMs 的总浓度范围在 21 至 373μg/L 之间，而这两个城市的总 THMs 浓度平均值分别为 142μg/L 和 260μg/L。氯仿是导致 THMs 浓度升高的主要因素之一（>85%）。THMs 的出现顺序为：氯仿、溴二氯甲烷>二溴氯甲烷>溴仿。通过不同的暴露途径（摄入、吸入和皮肤接触），使用预测模型对 THMs 的终生癌症风险进行了评估。发现拉瓦尔品第和伊斯兰堡的终生癌症风险平均值分别为 0.74×10(-4)和 1.24×10(-4)。每年预计每个城市的癌症病例数可能达到两例。这两个城市的危害指数值均低于 1，这意味着不会有显著的非癌症风险。对于这两种风险，口服摄入被认为是主要的暴露途径之一，其次是吸入和皮肤接触途径。
