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models developed earlier for other types of (low density) particles apply also to
plastic debris. A unique feature of plastic debris, however, is its combination of
high persistence, low density, and extremelywide size distribution, ranging from
thenanometer to the>cmscale.Thiscausesthesystembehaviorofplasticdebris to
show a far wider variety than most other materials or chemicals. We provide
recommendations for further development of these models and implications and
guidance for how fate and transport models can be used in a framework for the
tiered risk assessment of plastic debris.
Keywords Fate, Freshwater,Microplastics,Modeling,Nanoplastics
1 Introduction
Contaminationof the environmentwithplastic debris has received increasingatten-
tionfromthepublic,environmentalists, scientists, andpolicymakerssince the1970s
[1,2].Modelpredictionssuggest thatcurrentlyover5trillionplasticparticlesfloaton
theoceansurface[3]andthat in2010alonebetween4.8and12.7millionmetric tons
ofplastic entered theocean [4].Plasticsoccur inawide rangeof sizes, andparticles
can thereforebe ingestedbyavarietyof terrestrial [5]andaquaticspecies [6]. Inges-
tionofmicroplastics, particles<5mmin length [1], cannegatively affect hatching,
growth rates, and food ingestion [7, 8]. Besides the potential effect of ingestion,
plasticparticlescanactasvectors fororganicpollutants[9]orfunctionasfloatersfor
(invasive)raftingspecies[10].Theoccurrenceanddistributionofplasticdebris inthe
marineenvironmenthasbeenstudiedeveninthemostremoteareas,suchasthearctic
[11]andtheoceanfloor[12].However,eventhoughriversare recognizedasamajor
sourceofmarinelitter [13–15], theoccurrenceofplasticdebris infreshwatersystems
just started to receive attention [16, 17].
Microplastics have been found in freshwater systems around the world, as
summarized in a recent review by Eerkes-Medrano et al. [17]. Occurrence of
microplastics in freshwater systems ranges from remote lakes [18] to industrial
rivers such as the Rhine [15, 19] or St. Lawrence River [20]. Sources of plastic
debris in freshwater systems have not been studied extensively but likely include
effluents from wastewater treatment plants (WWTP), sewage sludge, shipping
activities, atmospheric fallout, direct disposal from thepublic, beach littering, and
runoff from agricultural, recreational, industrial, and urban areas [16, 21]. High
loads are estimated to enter themarine environment: for example, an average of
1,533 tplasticperyearwasestimated toenter theBlackSea fromtheDanube [13],
and an average of 208 t plastic per yearwas estimated to enter theMediterranean
from theRhone [22].However, river loads exhibit a high degree of variation. For
example, rain events were shown to increase the plastic concentration up to
150 times in an urban part of the Rhone catchment [22]. Also, total loads in the
Danube varied between 10.9 43.6 and 2.2 3.0 g (mean SD) per 1,000m3
from2010to2012[13], indicatingboththeuncertaintyintheloadestimatesandthe
temporal change of plastic loads. Transport of plastic near the bottomof the river
126 M.Kooi et al.
Freshwater Microplastics
Emerging Environmental Contaminants?
- Titel
- Freshwater Microplastics
- Untertitel
- Emerging Environmental Contaminants?
- Autoren
- Martin Wagner
- Scott Lambert
- Verlag
- Springer Open
- Datum
- 2018
- Sprache
- englisch
- Lizenz
- CC BY 4.0
- ISBN
- 978-3-319-61615-5
- Abmessungen
- 15.5 x 24.1 cm
- Seiten
- 316
- Kategorien
- Naturwissenschaften Chemie