Fate and environmental impact of the recently marketed herbicide Mesotrione: coupling biological and chemical studies for a global overview
Résumé
Enhanced knowledge of pesticide transformation products formed in the environment could lead to both accurate estimates of the overall effects of these compounds on environmental ecosystems and human health and improved removal processes. These compounds can present completely different chemical and environmental behaviour from the starting active ingredient and have a more important impact. Therefore the understanding of fate of the pesticide and its metabolites is crucial to really evaluate its environmental risk assessment. To reach this goal, biological and chemical studies have to be strongly correlated to obtain this global overview. Mesotrione, a recently marketed herbicide, was chosen as a case study to present the strategy used. Isolation of mesotrione-degrading bacteria, identification of its metabolites to establish its metabolic degradation pathway and determination of the toxicity of the active molecule and its transformation products are prerequisite to predict impact on the structure, diversity and function of environmental microbial communities.