N-NITROSODIMETHYLAMINE AS A HAZARDOUS CHEMICAL TOXICANT IN DRINKING WATER

Abstract

Nitrosamines is a family of potent carcinogens, have been of concern for many decades due to their occurrence in foods, industrial workplace environments, and as groundwater contaminants. Human exposure to nitrosamines can result from formation of N-nitroso compounds either in food during storage or preparation or in vivo, usually in the stomach. N-Nitrosodimethylamine is one of the main N-nitroso compound which is commonly found in drinking water and is a potent hepatotoxin, carcinogen and mutagen and it induces fibrosis and cirrhosis in liver. All identified health risks associated with N- Nitrosodimethylamine in drinking water incorporates all relevant routes of exposure from drinking water—namely, ingestion as well as skin absorption from showering and bathing. The toxicity produced by N-Nitrosodimethylamine is mediated by its reactive metabolites and not by the parent compound. Decontamination of N-Nitrosodimethylamine relies mostly on UV irradiation, but these methods are rather impractical and expensive when applied to municipal and wastewater treatment. N-Nitrosodimethylamine is reasonably anticipated to be a human carcinogen based on sufficient evidence of carcinogenicity in experimental animals. When administered orally, N-nitrosodimethylamine induced liver hemangiosarcomas, hepatocellular carcinomas, and kidney and lung tumors in mice. Reactive oxygen species have been implicated as causative agents in many degenerative diseases, and also in the promotion phase in carcinogenesis. Toxic effects of N-nitrosodimethylamine, a potent carcinogenic and mutagenic substance, were also proposed to be due to reactive oxygen species formed by its metabolic activation. The mechanism by which N-Nitrosodimethylamine produces cancer is well understood to involve biotransformation by liver microsomal enzymes, generating the methyldiazonium ion.