Major contribution of bisphenol A to estrogenic activity in landfill leachate as revealed by effect-directed analysis
Résumé
Landfill leachates are contaminated by a wide diversity of organic compounds and especially by endocrine disrupting chemicals. These complex mixtures can be leached into soils and groundwaters by advective transfer through holes or diffusion through geosynthetic liners and constitutes a risk for aquatic ecosystems. Because of complexity and variability of these matrices and the restricted number of molecules focused in targeted chemical analyses, selection of relevant molecules for environmental monitoring is often laborious. Effect-directed analysis combining fractionation step, with chemical and biological analyses might allow to identify the compounds responsible for observed effects. Investigations were conducted on an untreated leachate of municipal waste disposal. After a fractionation step by RP-HPLC, estrogenicity of crude extract and 40 fractions was assessed by in vitro bioassay on the reporter cell line MELN. An estrogenic activity (260 ng EQQ/L) was detected in raw extract of landfill leachate. In order to bring out estrogenic molecules not targeted by chemical analysis in the global extract, this extract was fractionated. Effect-directed analysis, used in this work, allows to identify bisphenol A as main contributor to estrogenic activity in this landfill leachate and brings to light the presence of polar estrogenic compounds. This method can be valuable to prioritize hazardous molecules in landfill leachates.