Utilization of drinking water quality index by bioassays detecting initiation and promotion activity

致癌过程除了起始活性外，还需要促进活性。在本研究中，使用小鼠成纤维细胞进行转化试验作为促进活性的指标，使用中国仓鼠肺细胞进行染色体畸变试验作为起始活性的指标。本研究旨在探讨生物检定结果与氯化副产物产生的关系，以作为水质管理中的水质指标。另一方面，在基因损害致癌物的情况下，根据终生致癌率确定了水质标准值。也就是说，它最初应该评估的不是化学品的瞬时浓度，而是综合毒性。从这一观点出发，对本财政年度沃茨的时间序列波动进行了测量。除了琵琶湖南部之外，还选择淀川的一个地点（大坂府平方市的一个地点）作为污染程度略有提高的地点。每月一次通过水取样进行检查。测定结果表明，氯仿作为促进活性的指标是合适的，同时，对琵琶湖水进行氯化处理后，引发活性降低，促进活性增加。非二步转化试验表明，饮用水在给水管网中的致癌性降低。研究结果表明，MX可代替三卤甲烷作为给水管网的水质指标。

Promotion activity in addition to initiation activity is needed for the process of the carcinogenesis. Transformation test using the mouse fibroblast cell is carried out in this study as an index to promotion activity, and chromosomal aberration test using Chinese hamster lung cell is carried out as an index to initiation activity. The purpose of this research is to show water quality index in the water quality management by examining the relationship between bioassay result and produced chlorination by-products. On the other hand, a water quality standard value has been set on the basis of a lifetime carcinogenic rate in case of a gene damaging carcinogen. That is to say it should originally evaluate not moment concentration of a chemical but an integrated toxicity. The time-serial fluctuation in waters was measured in this fiscal year from this viewpoint. One site (a site in Hirakata City of Osaka Prefecture) in Yodo River was selected as the site where pollution a little is advanced, in addition to southern part of Lake Biwa. The examination was carried out by sampling water once a month. As a result of measurement, it was shown that chloroform was suitable as an index to the promotion activity.In the meantime, there were reduction of the initiation activity and increase in the promotion activity after chlorination of Lake Biwa water. Non-two step transformation test shows that carcinogenesis of dinking water would decrease in water distribution systems. The obtained results show that MX would be an appropriate water quality index in water distribution systems instead of trihalomethanes.