[Investigation on nitrosamine in drinking water in Huang Shi--a high-risk area of stomach cancer in Fujian province].

Huang Shi town in Fujian province is one of the high-risk area of stomach cancer in China with a standard mortality rate of 61.19/100,000 in males. Epidemiologic survey showed that it was related to the severe contamination of Mu-Lan river system by which the drinking water for the residents was provided. Thirty-three water samples in the summer and winter times, filtrated and unfiltrated, from different spots along this river system were collected. The concentrations of nitrite and nitrosamine were determined. NDMA, NDEA, NDPA, NDBA, NPIP and NMOR by GC-TEA and three unknown peaks preliminarily identified as non-volatile nitrosamine by LC-TEA could be detected in these samples. The kinds and the content of nitrosamine in the samples collected in the winter time were all significantly higher than those collected in the summer, P values were all less than 0.01. Its possible significance in the causes of gastrointestinal tumors is discussed.