Page - 73 - in Freshwater Microplastics - Emerging Environmental Contaminants?

samplingsites:one inadenseurbanenvironmentandone insuburbanenvironment [17]. Only fiberswere encountered and fragmentswere not detected. Throughout the year of monitoring (site 1), the atmospheric fallout ranged from 2 to 355 fibers m 2 day 1 (110 96 fibers m 2 day 1, mean SD), indicating a high annual variability. On site 2, the atmospheric fallout was estimated around 53 38 fibers m 2 day 1. When the levels on both sites are compared, the suburban site systematically showed fewer fibers than the urban one.We hypo- thesize that this difference can be explained by the density of the surrounding population,which isconsideredasaproxyof localactivity.However, thishas tobe confirmed through investigations at other sites. A suburban catchmentwith a separate sewer (wastewater and runoffwater are collected separately)was considered for the urban runoff (unpublished data). The Sucy-en-Brie (R1, Fig. 1) catchment area reaches 261 ha, and its impervious Fig. 1 MapofParisMegacity and locationof thevarious sampling sites [23] Table 1 Usedmethods and sampledvolumes for thevarious compartments Samplingmethod Sampledvolume Atmospheric fallout Acollection funnel Continuousmonitoring Urban runoff,WWTPeffluents,CSOs Automatic samplers 200–1,500mL Fibers in freshwater 80μmmesh size net 0.2–4m3 Fragments in freshwater 300μmmesh size net 50–200m3 Sources andFate ofMicroplastics inUrbanAreas:AFocusonParisMegacity 73