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Accueil du site > Thèmes de recherche > Atmosphère & environnement > 2.1. Dégradation des Composés Organiques Volatils et semi-volatils et formation d’aérosols secondaires > 2.1.2 Composés semi volatils (pesticides)

2.1.2 Composés semi volatils (pesticides)

The wide use of pesticides in agricultural applications is of some concern since they may have a significant environmental impact. Once a pesticide is applied in the field, it can be partitioned into the soil, water and atmosphere. Knowledge of the environmental fate of pesticides is important in order to assess the potential risks to human and animal health.

The atmospheric fate in the gas phase of a series of pesticides (chloropicrine, hymexazol …) has been investigated using the large European outdoor simulation chamber (Euphore, Valencia). The rate coefficients for the reactions with OH and ozone have been measured and the photolysis investigated. The results obtained indicate that both photolysis and reaction with OH radicals are the main gas phase loss processes of these pesticides in the atmosphere. The kinetic parameters enable to conclude that the studied pesticides will be oxidized near their emission sources and will have an impact on the local and regional scales. Some of the degradation products have been identified and quantified which led us to derive the atmospheric degradation mechanisms for most of the studied pesticides. For example, phosgene (a highly toxic chemical) was found to be the major photolysis product of chloropicrine. (e.g. ACL75, 83, 101). This work has been supported by the INTERREG IIIC programme.