Department of Environmental Sciences, Jahangirnagar University, Savar, Dhaka, Bangladesh.
Institute of Food Science & Technology (IFST), Bangladesh Council of Scientific & Industrial Research (BCSIR), Dhaka, Bangladesh.
Environ Sci Pollut Res Int. 2019 Jun;26(16):16316-16330. doi: 10.1007/s11356-019-05049-6. Epub 2019 Apr 12.
Formation of trihalomethanes (THMs) through excessive chlorination in the supplied water and its carcinogenic nature is a public health concern in many parts of the world, including a couple of neighboring countries in Asia. However, the issue was not yet addressed either in the public health policy or in academia in Bangladesh. Therefore, the objectives of this study are to determine the THM concentration in supplied water, its multiple pathways to the human body, and an estimation of resultant carcinogenic risk to urban dwellers in six different regions of Dhaka city. Thirty-one supplied water samples were collected from 31 different water points located in Purana Paltan, Naya Paltan, Kallyanpur, Shyamoli, Malibagh-Rampura, and Panthapath regions in premonsoon time. Total chlorine and chlorine dioxide (ClO) and trihalomethane (THM) concentration were determined using UV-VIS spectrophotometer; total organic carbon (TOC), total inorganic carbon, and total carbon concentration were measured using TOC analyzer, and chloroform concentration was determined by applying gas chromatography-mass spectroscopy (GC-MS-MS) in the supplied water samples. Research findings indicate that THM concentration exceeded the USEPA acceptable limit (80 ppb) in all regions except Panthapath. Study results showed that carcinogenic risk via ingestion was higher than the USEPA acceptable limit of 10. Carcinogenic risk via dermal absorption and inhalation exposure was lower according to USPEA acceptable limit. To conclude, this study represents the current knowledge about THM concentration in supplied pipeline water and adverse health risk, which signifies that regulatory measures should be taken to reduce the THM concentration.
在供应水中过度氯化形成的三卤甲烷（THMs）及其致癌性质是世界上许多地区，包括亚洲的几个邻国的公共卫生关注点。然而，这个问题在孟加拉国的公共卫生政策或学术界都尚未得到解决。因此，本研究的目的是确定供应水中的 THM 浓度、其进入人体的多种途径，以及对达卡市六个不同地区城市居民的致癌风险估计。在季风前时期，从位于帕拉坦、新帕拉坦、卡利扬普尔、沙莫利、马利巴格-兰普尔和潘塔帕思地区的 31 个不同供水点采集了 31 个供水样本。使用紫外可见分光光度计测定总氯和二氧化氯（ClO）和三卤甲烷（THM）浓度；使用总有机碳（TOC）分析仪测定总有机碳、总无机碳和总碳浓度；通过气相色谱-质谱联用仪（GC-MS-MS）测定水中的氯仿浓度。研究结果表明，除潘塔帕思地区外，所有地区的 THM 浓度均超过了 USEPA 可接受限值（80 ppb）。研究结果表明，通过摄食摄入的致癌风险高于 USEPA 可接受限值 10。根据 USEPA 可接受限值，通过皮肤吸收和吸入暴露的致癌风险较低。总之，本研究代表了关于供应管道水中 THM 浓度和不良健康风险的最新知识，这表明应采取监管措施来降低 THM 浓度。
