Abstract:
Disinfection is an important process to make the water free from harmful pathogenic substances, but sometimes it results in the formation of harmful by-products. Development of predictive models is required to define the concentration of THMs in pool water. Majority of studies reported inhalation to be the most significant THMs exposure route which is more likely to be dependent upon the concentration of THMs in pool water and in air. THMs concentration in the analyzed pool water samples and in air was found to be 197.18 ± 16.31 μg L-1 and 0.033 μg m3-1, respectively. Statistical parameters such as high correlation coefficients, high R2 values, low standard error, and low mean square error of prediction indicated the validity of MLR based linear model over non-linear model. Therefore, linear model can be most suitably used to pre-assess and predict the THMs levels in swimming pool water. Risk estimation studies was conducted by using the united states environmental protection agency (USEPA) Swimmer Exposure Assessment Model (SWIMODEL). The lifetime time cancer risk values related to chloroform exceeded 10-6 for both the sub-population. Inhalation exposure leads to maximum risk and contributed up to 99% to total cancer risk. Risk due to other exposure pathways like accidental ingestion and skin contact was found to be negligible and insignificant. Monte Carlo simulation results revealed that the simulated THMs risk values for the studied exposure pathways lies within ±3.1% of the average risk values obtained using SWIMODEL. Hence, the risk estimates obtained using SWIMODEL seemed to be appropriate in determining the potential risk exposure of THMs on human health. Variation in input parameters like body weight (BW) and skin surface area (SA) leads to difference in risk estimates for the studied population. Non cancer risk was found to be insignificant as represented by low hazard quotient (HQ < 1) values. Through monitoring and regulations on control of THMs in swimming pool water is required to minimize the risk associated.
摘要:
消毒是使水中不含有害致病物质的重要过程,但有时会导致有害副产品的形成。需要开发预测模型来定义池水中THM的浓度。大多数研究报告说,吸入是最重要的THM暴露途径,这更可能取决于泳池水和空气中THM的浓度。分析的池水样品和空气中的THM浓度分别为197.18±16.31μgL-1和0.033μgm3-1。高相关系数等统计参数,高R2值,低标准误差,预测的均方误差较低,表明了基于MLR的线性模型优于非线性模型的有效性。因此,线性模型最适合用于预先评估和预测游泳池水中的THMs水平。通过使用美国环境保护局(USEPA)游泳者暴露评估模型(SWIMODEL)进行风险估计研究。对于这两个亚群,与氯仿相关的终生癌症风险值超过10-6。吸入暴露导致最大风险,并对总癌症风险贡献高达99%。由于意外摄入和皮肤接触等其他暴露途径引起的风险被发现可以忽略不计且微不足道。蒙特卡洛模拟结果表明,所研究暴露途径的模拟THMs风险值与使用SWIMODEL获得的平均风险值相差±3.1%。因此,使用SWIMODEL获得的风险估计值似乎适用于确定THM暴露对人类健康的潜在风险.输入参数如体重(BW)和皮肤表面积(SA)的变化导致所研究人群的风险估计差异。发现非癌症风险不显著,如低风险商(HQ<1)值所示。通过对游泳池中THM控制的监测和规定,需要将相关风险降至最低。