N-nitrosamines, emerging disinfection by-products of health concern: an overview of occurrence, mechanisms of formation, control and analysis in water

The presence of N-nitrosamines in water bodies used for drinking water purposes may present a more serious risk for humans than regulated disinfection by-products (DBPs) species. Hence, understanding and controlling the incidence of N-nitrosamines represents a contemporary challenge to the water industry. Although many of these molecules potentially formed as DBPs are detected in chlorinated natural waters, few studies have focused on the formation, occurrence, and analysis of N-nitrosamines. Until now, nine N-nitrosamines have been detected in water samples; N-nitrosodimethylamine is the most frequently reported nitrosamine in drinking water. Although there are currently no federal regulations for these molecules in drinking water, this family of N-DBPs is one of three potential groups of contaminants highlighted for possible regulatory action in the near future. This paper gives an overview of the current knowledge concerning the occurrence, precursors, and formation mechanisms of N-nitrosamines in water. In addition, the existing regulations are described and relevant analytical methods used for their quantification in water samples are also discussed.