Organophosphate ester (OPE) flame retardants and plasticizers and microplastics (MPs) are emerging threats to the marine environment, presenting multiple sources in the environment and being widely distributed in sea and ocean of the planet. Marine sediments are thought to be a sink for both OPEs and MPs. In addition, leaching from MPs could constitute in-situ sources of OPEs. Therefore, determining their environmental occurrence in sediments becomes crucial to better understand their current stocks, the exposure of benthic organisms, and possible impacts on the global functioning of marine ecosystems. The Loire is the longest river in France representing an important freshwater discharge to the North-East Atlantic Ocean. Its estuary is considered as an ecosystem of high ecological value as well as an ocean/land interface for sea trade and associated industrial activities. The overall objectives of this work were: (1) to determine the current environmental levels of OPEs and MPs in sediments and selected benthic organisms from the Loire estuary; (2) to investigate the OPE bioaccumulation (transfer sediment-benthos); and (3) to explore the links between MPs abundance and OPE concentrations in the study area. Two sampling campaigns conducted in September 2021 and November 2022 allowed the collection of surface sediments and the deposit feeder clam Scrobicularia plana (SP) in four study areas subjected to different anthropogenic pressures. Preliminary results from the first campaign in September are presented in this poster.