Pesticides nitrosamine formation

Possible exposure to pesticide-derived N,-nitroso compounds depends on environmental processes that influence formation, movement, and degradation of the compounds. Although laboratory studies have shown the feasibility of environmental nitrosamine formation, there has been little evidence that it is an important process. Nitrosamines vary greatly in their environmental stabilities, but all seem to be susceptible to one or more modes of decomposition including photolysis, microbiological degradation, and plant metabolism. 

The discovery of nitrosamine contaminants In some pesticides has led to a major technological effort to prevent, reduce or eliminate formation of these Inadvertent Impurities In pestlcldp formulations. Although the nitrosamine... 

Nitrosamines have been shown to be formed in soils in the presence of secondary amines and nitrite at acid pH values. ° Many agricultural chemicals contain structures that can be degraded to secondary amines. The excessive and widespread use of these pesticides may result in accumulation of secondary amines in localized environments, and may contribute to the formation of nitrosamines. 

Fertilization of arable lands and grassland soils with mineral nitrogen favors the formation of nitrosamines in soil. Formation of nitro and nitroso and other compounds has been observed, which are precursors of nitrosamines. They are also products of biotransformation of some pesticides and other precursors. Dynamics of the formation and development of nitrosamine precursors in soil depend on many physicochemical factors but soil acidification processes undoubtedly favor it. Once they are formed they remain in soils for between 90 and 128 days and in aquatic environment for 80-110 days. 

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