Seite - 225 - in Freshwater Microplastics - Emerging Environmental Contaminants?

argue that the cause-effect linkages of risks associatedwithmicroplastics are complex, leading togreat uncertainty in their scientific assessment. (c) Global risksarecharacterizedbyaspecificvibrancywhichaffectsother linked entities or systems. This can lead to impacts in systems other than the risk-producing system. Such linking may involve natural processes (such as ocean currents, wind) and social processes (like communication, practices). Therefore,we argue, thirdly, thatmicroplastics are vibrant, affecting not only ecosystemsbut different social, political, and economic spheres. (d) Global risks are differently perceived, interpreted, and framed, which is an impediment tomanagement strategies. Thismaybe due to the presentation of different kinds of evidence, leading to competing views, or to conflicting interpretationsof thesameevidence,producingwhat is referredtoasambiguity [10].Hence,weargue, fourthly, thatmicroplasticsareanexampleofacomplex problem,duenotonly touncertainty regarding theirnegativeeffectsbutalso to competingviewsonhow to combat the problem. In the following sections, these four arguments are elaborated by taking into accountdifferentaspectsof therecentscientificandpublicdebateonmicroplastics. 2 ThePlasticDilemmaandEverydayModesofRisk Production Microplastics emerged as a scientific topic about 10 years ago and recently came into public awareness when the debate focused on their release from cosmetic products and potential abundance in human food [11–15]. But are microplastics reallyanewphenomenonorcanweregard themasanewlydiscoveredsymptomof an old problem, the problem of plastic pollution? As indicated in the quotation below, microplastics, called “plastic particles,” were recognized as part of the problem of plastic pollution in coastal and oceanic waters in the 1970s, though the associated adverse consequenceswere considered asminor compared to other contaminants: Atthepresent levelsofabundanceofplasticparticles incoastalandoceanicwaters,adverse biological consequenceswould appear to beminor compared to the deleterious effect of other contaminants such as petroleum residues and other chemical wastes. Increasing production of plastics, combinedwith present waste disposal practices, will undoubtedly lead to increases in the concentration of these particles in rivers, estuaries, and the open ocean. [16] Plastic has been knownas a factor in environmental pollution—symbolized by theplastic bag—for a long time.Looking at newspaper headlines dealingwith the environment-plastic nexus, it becomes clear that plasticwaste in the environment has been perceived as an environmental problem at least since the 1970s (see Table 1 forTheNewYorkTimesheadlines). Understanding theRisks ofMicroplastics:ASocial-EcologicalRiskPerspective 225