Carcinogenic effects of N-nitroso compounds in the environment

N-nitroso compounds (NOC) are produced by the acid catalyzed reaction of nitrite with certain nitrogen compounds. The gastrointestinal tract (GI) is the main site for the formation of reactive nitrogen species (RNS). Bacteria present on the GI tract surface reduced the dietary nitrate or nitrite into Nitric oxide NO and other related compounds. The clinical sign of NOC carcinogenicity varies according to species, dose, and route of administration. Humans are exposed to preformed N-nitroso compounds and endogenous NOC via the environmental food chain. Several NOC are potential human carcinogens, including DENA and NDMA, but evidence from population studies is inconsistent.