Volatile nitrosamine levels in common foods from Tunisia, south China and Greenland, high-risk areas for nasopharyngeal carcinoma (NPC).

On the basis of anthropological pilot studies on diet in Tunisia, south China and Greenland, food items consumed frequently by these populations at high risk for NPC were analysed for volatile nitrosamines using gas chromatography combined with a thermal energy analyzer. Relatively high levels of N-nitrosodimethylamine (NDMA), N-nitrosopyrrolidine (NPYR) and N-nitrosopiperidine (NPIP) were detected in Tunisian stewing base ("Touklia") and dried mutton preserved in olive oil ("Qaddid"). NDMA was also detected at levels ranging from trace amounts to 133 micrograms/kg in several Chinese salted and dried marine fish and in Greenland dried, unsalted fish preparations. NPYR and NPIP were also occasionally detected in several vegetables fermented in brine collected in Tunisia and China. The possible role of nitrosamines in the etiology of NPC is discussed.