A source-to-sink perspective of an anthropogenic marker: A first assessment of microplastics concentration, pathways, and accumulation across the environment

Source-to-sink geoscientific domain and environmental plastic cycle studies are two major scientific worlds starting to interact, taking benefit from each other. To advance in our understanding of the sharing benefits between interconnecting research communities, we firstly carry out a review from sedimentology, sources, sinks, transport dynamic and pathways of microplastics along the entire source-to-sink (S2S) profile. The main peculiarities for microplastics are the numerous and distributed sources across the environment, as well as the importance of physical properties and shape factors. Then, we propose a review of plastic mass concentration along the S2S profile to discuss influence of sedimentation rate on microplastic accumulation and to identify intermediate reservoir and final fates. Deep sea deposits, including turbidite systems are potentially hotspots for microplastic accumulation that are poorly studied, deserving much more attention to scale mass balance studies. This review finally highlights areas of synergies between S2S geoscientific and plastic communities to guide future interdisciplinary microplastic research. Most of these issues will rely on multiplying measurements across all matrices and environments based on standard technology to generate homogenized measurements and large database for plastic and microplastics.