Massive accumulation of plastic particles has been reported for marine ecosystems around the world, posing a risk to the biota. Freshwater ecosystems have received less attention despite most plastic litter being produced onshore and introduced into marine environments by rivers. Some studies not only report the presence of microplastics in freshwater ecosystems, but show that contamination is as severe as in the oceans. In continental waters, microplastics have been observed in both sediments (predominantly lake shores but also riverbanks) and water samples (predominantly surface water of lakes and rivers). This review highlights recent findings and discusses open questions, focussing on the methodology of assessing this contaminant in freshwater ecosystems. In this context, method harmonisation is needed in order to obtain comparable data from different environmental compartments and sites. This includes sampling strategies (at spatial and temporal scales), sample treatment (taking into consideration high levels of organic matter and suspended solids) and reliable analytical methods to identify microplastics.
Emerging contaminants, Freshwater ecosystems, Lakes, Plastic debris, Plastic separation, Polymer identification, Rivers, Sediment, Urban water
Dris, R., Imhof, H., Sanchez, W., Gasperi, J., Galgani, F., Tassin, B., Laforsch, C., 2015b. Beyond the ocean: Contamination of freshwater ecosystems with (micro-)plastic particles. Environmental Chemistry 12(5): 539–550.
This study investigates the microplastic contamination of both urban compartments (wastewater and total atmospheric fallout) and surface water in a continental environment. These first investigations on an urban environment confirm the presence of microplastics in sewage, fresh water and total atmospheric fallout and provide knowledge on the type and size distribution of microplastics in the 100–5000-µm range. For the first time, the presence of microplastics, mostly fibres, is highlighted in total atmospheric fallout (29–280 particles m–2 day–1). High levels of fibres were found in wastewater (260–320 × 103 particles m–3). In treated effluent, the contamination significantly decreased to 14–50 × 103 particles m–3. In the River Seine, two sampling devices were used to collect both large and small microplastic particles: (i) a plankton net (80-µm mesh), and (ii) a manta trawl (330-µm mesh). Sampling with the plankton net showed a predominance of fibres, with concentrations ranging from 3 to 108 particles m–3. A greater diversity of both microplastic shapes and types was found during manta trawl sampling but at much lower concentrations (0.28–0.47 particles m–3). This combined approach could be relevant and implemented in future studies to provide an accurate overview of microplastic distribution in freshwater.
Atmospheric fallout, Freshwater, Rivers, Synthetic fibres, Urban environment
Dris, R., Gasperi, J., Rocher, V., Saad, M., Renault, N., Tassin, B., 2015a. Microplastic contamination in an urban area: A case study in Greater Paris. Environmental Chemistry 12(5): 592–599.