Page - 63 - in Freshwater Microplastics - Emerging Environmental Contaminants?

samplingof thedifferentcompartments,areakeyfactorformeaningful results.The quantitation of microplastics differs due to the individual sampling method and studies still lacking in comparability. Therefore, future studies should integrate additional units to describemicroplastic occurrence in their investigations.More- over,an integral stepof future investigationsshouldbeasufficientvalidationof the microplasticanalysis, asdifferent technologicalapproachesmightbeusedorfuture technological improvements will be implemented for the determination of microplastics. Important approaches, such as Raman-, FTIR-, and GC/MS-based techniques, seemtobeveryversatile for thedetectionofmicroplastics, but abetter comparability of results obtained with either of these methods needs to be established.Degradation of larger plasticswill result in a constant source for new microplastic particles of all size classes, and thus, as it is a slow process, microplasticswill be a relevant long-term threat. Acknowledgments Wewould like to thank the German Federal Ministry for Education and Research (BMBF) in the frame of the project microplastics in the water cycle (MiWa; FKZ: 02WRS1378D). References 1.Hidalgo-Ruz V, Gutow L, Thompson RC, Thiel M (2012) Microplastics in the marine environment: a reviewof themethods used for identification and quantification. Environ Sci Technol 46(6):3060–3075. doi:10.1021/es2031505 2.L€oder MGJ, Gerdts G (2015) Methodology used for the detection and identification of microplastics—a critical appraisal. In: Bergmann M, Gutow L, Klages M (eds) Marine anthropogenic litter. Springer International Publishing,Cham, pp201–227. doi:10.1007/978- 3-319-16510-3_8 3.NgKL,Obbard JP (2006)Prevalenceofmicroplastics inSingapore’s coastalmarineenviron- ment.MarPollutBull 52(7):761–767. doi:10.1016/j.marpolbul.2005.11.017 4.Nore´n F, Naustvoll L-J (2010) Survey ofmicroscopic anthropogenic particles in Skagerrak. CommissionedbyKLIMA–OgForurensningsdirektoratet 5.Casta~neda RA, Avlijas S, Simard MA, Ricciardi A (2014) Microplastic pollution in St. Lawrence River sediments. Can J Fish Aquat Sci 71(12):1767–1771. doi:10.1139/cjfas- 2014-0281 6.Van Cauwenberghe L, Vanreusel A, Mees J, Janssen CR (2013) Microplastic pollution in deep-sea sediments. EnvironPollut 182:495–499. doi:10.1016/j.envpol.2013.08.013 7.ZbyszewskiM,CorcoranPL,HockinA(2014)Comparisonofthedistributionanddegradation of plastic debris along shorelines of theGreat Lakes, NorthAmerica. J Great Lakes Res 40 (2):288–299. doi:10.1016/j.jglr.2014.02.012 8. Imhof HK, Ivleva NP, Schmid J, Niessner R, Laforsch C (2013) Contamination of beach sediments of a subalpine lake with microplastic particles. Curr Biol 23(19):R867–R868. doi:10.1016/j.cub.2013.09.001 9.BrowneMA, Galloway TS, Thompson RC (2010) Spatial patterns of plastic debris along Estuarine shorelines. EnvironSciTechnol 44(9):3404–3409. doi:10.1021/es903784e 10.KleinS,WorchE,KnepperTP (2015)Occurrenceand spatial distributionofmicroplastics in river shore sediments of the Rhine-Main area in Germany. Environ Sci Technol 49 (10):6070–6076. doi:10.1021/acs.est.5b00492 Analysis,Occurrence, andDegradation ofMicroplastics in theAqueous. . . 63