Abstract
AbstractN‐Nitroso compounds are a diverse group of hundreds of potentially toxic and carcinogenic chemicals. Of these, the most well studied are chemically simple nitrosamines, such as dimethylnitrosamine (DMN) and diethylnitrosamine (DEN), both of which are remarkably potent causes of cancer in all animal‐species so far tested; and likely to be carcinogenic to humans as well. This chapter addresses how our exogenous exposures to these and related compounds—both occupationally and environmentally—have changed over the decades. Notably, DMN and some otherN‐nitroso compounds are also formed endogenously, in all animals, including humans: mechanisms of this endogenous nitrosation are discussed herein. The chemistry and metabolism of selected nitrosamines are presented, especially as these relate to the formationin vivoof the proximately toxic and carcinogenic chemical‐species. Nitrosamine exposures via cigarettes are detailed, as are (historical and current) occupational exposures, such as via rubber‐manufacturing, and via some metal lubricating fluids. General environmental exposures via food, beverages, and pharmaceuticals are also discussed.