Preformed N-nitroso compounds in foods and beverages.

Most western-style foods have been analysed for the presence of volatile N-nitrosamines. Relatively few foods consistently contain detectable (greater than 0.1 microgram/kg) amounts of volatile N-nitrosamines. The major known contributors to dietary volatile N-nitrosamines are nitrite-cured meats, particularly fried bacon, and beer. The amount of volatile N-nitrosamines in these foods has declined in recent years. Average dietary intakes of preformed volatile N-nitrosamines have been calculated from these data and indicate that dietary exposure for consumers of western-style foods amounts to 0.5 to 1.0 microgram/day/person. Asian foods have not been surveyed to the same extent but preliminary data indicate a somewhat higher and more frequent volatile N-nitrosamine content, in part due to differences in fish intake and preparation. Indirect evidence suggests that the non-volatile content of some foods may be one to three orders of magnitude higher than volatile N-nitrosamine content.