Probabilistic exposure assessment to total trihalomethanes in drinking water: an EVT method

Byline: Norio Okada, Wei-Bin Yu, Ying Fan, Hiroshi Tsuno, Yi-Ming Wei It was proved that some adverse reproductive outcomes are associated with the exposure to trihalomethanes. We define the exposure as the probability with which the total trihalomethanes concentration in drinking water exceeds the maximum level. We apply the Peaks of Threshold model of Extreme Value Theory into assessing the exposure risk for the drinking water in Japanese distribution systems. The empirical results indicate the formation and exposure risk of total trihalomethanes will be affected by city position, treatment condition and chlorination method. And according to WHO's and Germanic maximum level, Japanese drinking water is still far from safe for individuals.