[Non-volatile nitrosamines in some foods from Linxian County].

For the incidence of non-volatile nitrosamines in the staple foods and vegetables, corn, millet, turnip and turnip chips collected from Linxian County Henan Province, a high incidence area of esophageal cancer, were collected, analyzed and compared with the foods from Huairou County Beijing, a low risk area. Nitrososarcosine (NSAR), nitrosoproline (NPRO) and two unknown non-volatile compounds were found in the food samples from Linxian, and the levels of NSAR in corn ranged 0.7-1.1 ppb and in turnip chips ranged 20.5-962.5 ppb. NSAR level detected in corn samples from Huairou County was not significantly different from that of Linxian. The possibility that the high content of nitrosamines in turnip chips is due to microbial infections is discussed.