新潟県における河川水中および水道水中の除草剤クロルニトロフェン(CNP)およびCNPアミノ体の動態について
1994 年 48 巻 6 号 p. 1090-1098
詳細
1994 年 48 巻 6 号 p. 1090-1098
It has been reported that the standardized mortality ratios (SMRs) of biliary tract cancer (BTC) (female gallbladder cancer (GBC) in particular) are high in the Niigata plain and low in other parts of Niigata Prefecture. Based on epidemiological studies, the presence of environmental water pollution by agricultural chemicals is likely to be associated with the occurrence of GBC, and one of the most suspected of these is a diphenylether herbicide, chlornitrofen (CNP).
The purpose of the present study was to investigate whether or not there was a difference in concentrations of CNP and its reduction product (CNP-amino) in river and faucet water between Niigata and Joetsu Cities, which are located in the Niigata plain and another part of Niigata, respectively. By employing a new method for CNP and CNP-amino extraction, the detection of CNP and CNP-amino was undertaken by using a gaschromatograph with an electroncapture detector.
The maximum levels of CNP concentrations were 871 and 554ng/l in river and faucet water, respectively on May 6, 1992 in Niigata City. The concentration of CNP in faucet water was well correlated with that in river water. In Joetsu City, the maximum concentration in river water was 183ng/l on May 6 and had decreased rapidly towards the background level on July 29, 1992. As to the concentrations of CNP in faucet water in Joetsu City, they fluctuated between the levels of 2 and 9ng/l. In the case of CNP-amino concentrations in faucet water, a clear-cut difference was evident between the two cities; 384ng/l in Niigata and under the quantity limit in Joetsu.
Examination of CNP and CNP-amino concentrations in faucet water was made in Murakami, Gosen and Kamo Cities, where the SMRs for female GBC were insignificant even in the midst of the Niigata plain. It was demonstrated that concentrations of CNP and CNP-amino were as low as in Joetsu City. The levels of pollution of faucet water with CNP and CNP-amino were well correlated with the SMRs of BTC, especially female GBC.
