Phototransformation of pesticides in the environment

This chapter presents the main photoinduced transformation processes involving pesticides molecules in sunlit surface waters, on soil and in the atmosphere (taking into account both the gas and the condensed phase). Moreover, a recently developed model approach to predict pollutant phototransformation in surface waters is presented and described, together with an example referred to the herbicide MCPA (4-chloro-2-methylphenoxyacetic acid) and to the production of the toxic transformation intermediate 4-chloro-2-methylphenol.