Seite - 263 - in Freshwater Microplastics - Emerging Environmental Contaminants?

expired. Hence, regulatorymeasures in early product life stages shouldminimize plasticwaste that couldbe released into the environment. However, currently (micro)plastics enter freshwater systems, and monitoring programs need to evaluate the environmental status quo to develop adequate measures. For instance, the type of (micro)plastic and its entry path into the environment should be considered:Depending on their application, plastics enter the environment as macroplastics, secondary microplastics, or primary microplastics (for definition, see [3]). The regulation of primaryMP seems to be closer related to the regulationofchemicalpollutants: production, application, and entry into the environment are traceable to a certain extent. In freshwatermonitor- ing, sourceandpolluter canpotentiallybe identified, similar to chemical polluters. It has to be noted that the application of some primary MPs even accepts its intended entry into the water cycle, for instance, in the application of MPs in personal care products or as blasting abrasives for cleansing of surfaces (e.g., wheel rimsof cars; [69, 70]). SecondaryMPs, incontrast, arenot easily traceabledue to their various sources andentrypathways.Astotheirpotentiallylongfate intheenvironment, thepolluter can rarely be identified, and, as a result, it is hardly possible to apply the polluter- pays principle. Secondary MPs usually originate from larger plastic products, which are originally intended to be correctly recycled or disposed. Incorrect disposal (by purpose or because of lackingwastemanagement) leads to fragmen- tationanddistributionof smaller particles inenvironmental systems.Thus, regula- torymeasures should intervenebeforeanunintended fragmentationofplastics into MPscanoccur.Reasonable strategies shouldhavepositiveeffectsonaglobal level andshouldbeable toprevent the (micro)plasticproblemseven in regions that lack properwastemanagement (see [32]). 3.5 StandardizationofSamplingandAnalysis The implementation of any regulation measure implies the existence of reliable monitoringdata on the status quo and temporal trends in the environment. In environmentalmonitoring for regulatory purposes, standardized and harmo- nizedprocedures are aprerequisite for reliable, generally accepted, and justiciable data acquisition. On several conferences on plastics in the environment, stake- holders agreed that there is a considerable – not to say a complete – lack of standards for sampling, sample preparation, chemical analysis, and the analysis of biologicaleffects in thefieldofplasticcontamination.Afundamentalchallengelies in the fact that the issue of plastic materials in different environmental compart- ments differs from classical environmental monitoring and assessment issues. Classicalmonitoring of chemical contamination, e.g., according to the EUWFD, mainly addresses dissolved or particle-bound chemicals in the waterbody or in biota. The plastic contamination issue concerns undissolved material with an extremely inhomogeneous distribution pattern. Up to now, knowledge about FreshwaterMicroplastics:Challenges forRegulation andManagement 263