Impacts of MicroPlastic in Agrosystems and Stream Environments

The Norwegian Institute for Water Research

Impacts of MicroPlastic in Agrosystems and Stream EnvironmentsResults from an international research project on sources, behaviour and ecological impacts of microplastics from sewage sludge application to agricultural soils

“We found that the application of biosolids from sewage sludge represents an important source of microplastics (MPs) to agricultural soils. Soils that received more biosolid treatments in the past exhibit higher levels of MPs, demonstrating progressively increasing pollution. Soil organisms underpinning important ecological and agricultural functions interact with these MPs, experiencing sublethal health effects at realistic environmental concentrations. Soil is a non-renewable resource and soil MP pollution is irreversible. To enable sustainable and circular use of sewage sludge, measures that prevent MPs from accumulating in it, or that remove them prior to use are necessary”.

— IMPASSE team

18 Detailed Report of Results

Exposure

Impacts

19

24

Decision-supporttool

Stakeholders

27

29

Scenarioassessment 31

34 Conclusions & Recommendations

37 Publications

39 About the Consortium

40 Credits

40 Acknowledgements

5 Note from the Coordinator

Luca Nizzetto

Contents

7 Executive Summary In2016,agroupofscientistsfromtheNorwegianInstituteofWaterResearchandtheSwedishUniversityofAgriculture(thatlaterseededtheformationoftheIMPASSEconsortium)publishedaseminalperspectivepaperonthepagesofEnvironmentalScience&Technology.1Thatshortarticledrewtheoreticalconsiderationsontheroleofsewagesludgeapplicationassoilamendmentinagriculture(acommonpracticeinEuropeandNorthAmerica)asapotentialmajorsourceofplasticpollutiontotheenvironment.Atthattime,onlyfragmentarydatawereavailableontheloadsofMPsinsewagesludge.Novalidatedmethodwasinplacetoaccuratelymeasuremicroscopicplasticfragmentsincomplexenvironmentalmatricessuchassludge,soilsandsediments,andnoscientificpeer-reviewedstudieshaddirectlyaddressedorhighlightedthispotentialenvironmentalproblem.Usinglife-cycle-derivedindirectestimatesofsourcesofMPstowastewaterandtheknowledgethatmostoftheseMPsareretainedinsewagesludgeduringwastewatertreatment,theauthorsconductedaninitialestimateoftheexpectedloadsofMPspotentiallyreachingagriculturalsoils.Throughthesecalculations,itwasestimatedthatbetween63000−430000tonsand44000−300000tonsMPsareaddedyearlytoEuropeanandNorthAmericanfarmlands,respectively.Thiswouldbeanalarminglyhighinput.

Thispaperhadaconsiderableresonanceamongstacademics,stakeholdergroupsandthegeneralpublic.ItcontributedtoinitiateseveralinternationalresearchprogramsfocusedonassessingthesourcesandimpactsofMPsinterrestrialenvironments,whichwaspreviouslyoverlookedinplasticpollutionresearch(adisciplinethatemergedfromtheareaofmarinesciences).Theprovidedestimatesshedafirstlightontheperspectivethatsometerrestrialenvironmentscouldbesignificanthotspotsofthispollution,andthus,potentialsourcesofMPstofreshwaterandmarineenvironments.Atthattime,empiricalevidencescapableofconfirmingorrejectingthosetheoreticalestimateswerelimitedandhinderedbythelackingcapacitytomeasureMPsincomplexsolidenvironmentalmedia.Similarly,atthatstage,onlyafewexperimentalassessmentsoftheeffectsofMPsonsoilandfreshwaterorganismswereavailable,generallyreportingresultsforunrealisticallyhighexposurelevels.AsaconsequenceofthislackofempiricallygroundedawarenessonthepressureandimpactsofMPpollutioninsoil,thepolicydebateonthesafeuseofbiosolidsinagriculturehasbeen,uptonow,mainlybasedonnarrativesandpositionsthatcouldbeeasilyaffectedbyinsufficientevidence.

TheprojectIMPASSE(ImpactsofMPsinAgroSystemsandStreamEnvironments)wasconceivedtofilltheseknowledgegapsthrougharigorousempiricistapproach.Thisresearchwasenabledbysignificanteffortstoconsolidatemethodology2anddevelopinganobjectiveandareliablequantitativeanalysisofMPoccurrenceinbiosolids,soilsandsediments.Similarly,wedesignednewsetsofreferencematerialsfortoxicologicaltesting.Wedeployedthesethroughacomprehensivearrayoftoxicologicaltests(coveringabroadspectrumofterrestrialandaquaticorganismswithkeyecologicalandagriculturalfunctions)toinvestigatethedirectandindirecteffectsofMPsincludingrealisticconcentrations.

Note from the Coordinator

LucaNizzettoisaLeadScientistattheNorwegianInstituteforWaterResearch(NIVA),whereheconductresearchon anthropogenic pressure andimpactsonthenaturalenvironmentandecosystemservices,includingresearchonchemicalandplasticpollution.DrNizzettoisthefunderoftheInternationalKnowledgeHubagainstPlasticPollution(IKHAPP)andthecoordinatoroftheEU-fundedinternationalprojectPAPILLONS(PlasticsinAgriculturalProduction:Impacts,Life-cyclesandLong-termSustainability).NIVAisaleadingInternationalresearchinstitutedevotedtomultidisciplinaryenvironmentalresearch,coveringtheareasofbiodiversity,climate,pollution,sustainabilityandgreentransition.

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Microplastics(MPs)areincreasinglyseenasanenvironmentalproblemofglobalproportions.TheconcernofMPsinsoilshaslargelybeenoverlooked;ThereisalackofknowledgeregardingtheconsequencesofMPpollutionforagriculturallandscapesandfreshwaters,especiallyinrelationtotheapplicationofsewagesludgeasasoilamendingagentinfarming.WastewaterTreatmentPlants(WWTPs)receivelargeamountsofMPsemittedfromhouseholds,industryandsurface/roadrun-offinurbanareas.MostoftheseMPsareretainedinthesewagesludge.Inmanycountries,WWTPsludgeisconvertedintobiosolidsandappliedtoagriculturalfieldsasasupplementtotraditionalfertilizers.Currently,MPspresenceinsewagesludgeisnotontheregulatoryagenda.IMPASSEwasoneofthefirstresearchprojectstodealwiththisissueinternationally.Theproject’soverallobjectivewastoinvestigatetheloads,fluxesandpotentialecologicalimpactsofMPsinfarmingcasestudiesinEuropeandCanadaanditdedicatedlaboratoryexperimentstoprovidefarmers,thewaterindustryandregulatorswithscientificallyinformedperspectivesontheenvironmentalimplicationsofMPcontaminationfrombiosoliduseinfarming.

IMPASSEisaninitiativeofsixresearchinstitutesinEuropeandCanadaandwassupportedundertheframeworkoftheEUERA-NETschemethroughWaterWorks2015callfinancedbynationalagenciesinNorway,Sweden,Spain,Canada,theNetherlandsandSlovenia.Itwasoneofthefirstinternationallyfundedprojectstotacklesources,behaviourandimpactsofMPsinterrestrialenvironments.ResultsfromIMPASSEaredescribedindetailinseveralpeer-reviewedpublicationsavailableintopinternationalscientificjournals(thecompletebibliographyisincludedattheendofthedocument).Thisreport,mainlydedicatedtodisseminationtowardssocietalactors,summarizesinclearterms(wehope)theseresultsandprovidesrecommendationsthatcancontributetoconsolidatetheongoingpolicydebateonthesafeuseofbiosolidsfromsewagesludgeinthecontextofacirculareconomy.

1. Nizzetto,L.;Futter,M.;Langaas,S.AreAgriculturalSoilsDumpsforMicroplasticsofUrbanOrigin?Environ.Sci.Technol.2016,50(20),10777–10779.https://doi.org/10.1021/acs.est.6b04140

2. Hurley,R.R.;Lusher,A.L.;Olsen,M.;Nizzetto,L.ValidationofaMethodforExtractingMicroplasticsfromComplex,Organic-Rich,EnvironmentalMatrices.Environ.Sci.Technol.2018,52(13),7409–7417.https://doi.org/10.1021/acs.est.8b01517.

Executive Summary

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Ecosystem ExposureWedeliveredthefirstvalidatedmethodfortheanalysesofMPsincomplex,organicmatter-richmedia(e.g.,sludge,soilsandsediments).Validationshowedtheabilityofaquantitative(70-98%)recoveryofMPsfromthesemedia.Linkedtothisvalidationwork,wedevelopedmethodsforproducingandcharacterizingnewreferencematerialsusingacocktailofMPssimilartothatfoundinsewagesamplestosupportecotoxicologicaltestingandqualityassuranceinMPanalyses.ThenewlydevelopedanalyticalmethodwasappliedtoanalysethesamplesfromcasestudylocationsinSpainandCanadawithcontrastingclimaticconditions,inwhichagriculturalsoilsaretreatedwithbiosolids.Inallcases,sludgesamplescontainedlargeamountsofMPs(AverageMPconcentrationsofbetween8,700MPkg-1and>14,000MPkg-1ofdrysludge),reinforcingresultsfromearlierassessmentsandtheoreticalexpectations.The application of biosolids represents an important source of MPs to agricultural soils.

De-wateringofsewagesludgeduringproductionofbiosolidsforagriculturaluseappearstoreduceMPcontent.MPswerefoundincontrolsoilswheretherewasnorecordofbiosolidsapplication,whichshowsthatotherMPsourcesexist.However,inallanalysedscenarios,MPconcentrationswereconsiderablyhigherinsoilswithahistoryofbiosolidapplications.ResultsfrombothcasestudiesshowthatMPsaremoreabundantinsoilsthathavereceivedmorebiosolidstreatments,indicatingeffective storage and the tendency of MP level to increase over time in these soils.DuringdroughtornormalprecipitationeventsverysmallreleasesofMPsfromsoilstowaterecosystemswereobservedinarunoffexperimentconductedinSpain(e.g.<0.1%ofthetotalMPcontentinsoilwerereleasedinoneyear).Whilethesetrendswereclear,dataonmassbudgetclosurewerestillaffectedbyalevelofuncertainty.Incontrast,intheCanadianscenarioevidenceshowedthatevenafewextremeprecipitationscanmobilizeasubstantialfractionoftheMPspresentinsoil.

MPsloadswereanalysedindifferentsectionsoftheriversdrainingthecatchmentswhereexperimentalfieldswerelocated.Polyethyleneandpolypropylenefragmentsandpolyesterfiberswerepredominantinthesesamples,roughlyreflecting(inqualitativeterms)thecontaminationprofileofwastewaterandsludge.

MPconcentrationsinriversedimentswerestronglydependentoncatchmentland-use,withpollutionlevelsincreasingsignificantlydownstreamofurbanandindustrialareasandwithhigherconcentrationsobservedinsedimentscollectedfromareaswithlowwaterflow.

IntheSpanishcasestudy,itwasestimatedthataround10billionsMPsaredischargedannuallyviawastewatereffluentsalone,whichrepresentabout50%oftheMPsriverdischargeunderbaselineconditions.Hence,undertheconditionsofthiscasestudy,agriculturalsourcesfromtheuseofsludgeappearednottobedominant.AsimilarfindingwasobtainedinCanadawhereamodel-basedmassbalanceapproachshowedthatagriculturalsourcesofMPstowaterecosystemsareexpectedtobecomedominantwhenbiosolidsareappliedto34%ofthetotalagriculturalland(currently,biosolidsareappliedtoonly2%).

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Impacts on soil and water organismsEffectsofdifferenttypesofMPs(Polyesterfibersandcartyrescrub)wereassessedonarangeofsoilorganisms(enchytraeidworms,earthworms,isopodsandspringtails)andfreshwaterorganisms(planktonicandbenthiccrustaceansandbenthicworms).Atenvironmentallyrelevantconcentrations,effectsareminimal;effectsonsurvivalwerenegligibleinallcases,howeverevidenceofinteractionsbetweenorganismsandMPparticles(e.g.,ingestionorentrainmentontheexternalpartofthebody)andarangeofsublethaleffectsonreproduction,massallocation,energystorageandlevelsofbiomarkerslinkedtoimmuneresponsewereobservedinsoilorganismsevenatenvironmentallyrepresentativeconcentrations(e.g.,ofhighlycontaminatedsoilsandsediments).ThisimpliesthatwhiletheacuteriskposedbyMPstosoilandwaterinvertebratesatenvironmentallyrelevantlevelsislow,prolonged exposure holds the potential to negatively affect a broad spectrum of organisms with different ecology and functions, some of which are key for sustaining agriculture.

Enchytraeidworms,earthworms,isopodsandwoodlousesingestedpolyesterfibers.Fibersextractedfromtheearthwormsandfromearthwormfaeceswereshorterthantheonesextractedfromthespikedfood,whichsuggests that earthworm activity in soil can transform polyester fibers to smaller sizes and thus increase the risk for their uptake by invertebrates.Bioconcentrationexperimentswereperformedonfish(Danio rerio)usingpolyethyleneMPsspikedwithorganicchemicalswithdifferentphysical-chemicalproperties(hexachlorobenzeneandchlorpyrifos)inordertostudytheinfluenceofMPsontheiruptakeandbioconcentration.ThelevelofthechemicalpollutantsmeasuredinfishtissuesslightlydecreasedinthepresenceofMPs,indicatingthatMPscanmodulateexposureandchemicalrisk,potentiallydecreasingit.Inaseparatesetofexperiments,MPswerealsofoundtomodulatetheeffectsofthepesticidechlorpyrifosonisopodsandspringtails.However,whilesomeparametersindicatedthatMPsreducedthebioavailabilityofchlorpyrifos,someotherparametersindicatedincreasedtoxicityofthepesticide.Microfiber addition to a soil mesocosm to simulate sewage sludge application did not seem to affect plant growth and earthworm abundance at fiber application rates up to 32 kg ha-1.

Experimentswithpolystyrenenanoplastics(withthemajordimensionrangingbetween20and100nm)werecarriedoutwithDaphnia(afreshwatercrustacean).NanoplasticsareordersofmagnitudesmallerthantheMPsstudiedinthepreviouslydescribedtestsandholdthepotentialtomigrateacrossbiologicalmembranesandaccumulateinsidecells.In this study, no significant effects were observed on zooplankton viability. Nanoplastics were, however, ingested and transported in the digestive tract and the outside of the carapace, suggesting the bulk of these materials did not enter the organisms’ cells.Eliminationofnanoplasticswasobservedafter3days.

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Decision support tool Multi-actor approach

We developed a new mathematical model of physical transport of MPs in the soil and freshwater at the watershed scale (INCA-MP).ThemodelisthefirstandonlyofitskindtosimultaneouslyaccountforthebudgetofMPsinterrestrialandriverenvironmentsasafunctionoftheirphysicalcharacteristics.AnexistingprototypewascompletelyrecodedandseveralnewfunctionsdescribingthephysicaltransportofMPsasdependentontheirsize,shapeanddensitywereadded.InadditionprocessessuchasfragmentationsofMPsandheteroaggregationinsoilandwaterwereincluded.

Themodelwassuccessfullyappliedtobothcasestudies(inCanadaandSpain).Both observed and modelled data demonstrated significantly higher MP concentrations of agricultural soils where biosolids had been previously applied, compared to agricultural soils with no history of biosolids application.ThemodelsuccessfullypredictedtheorderofmagnitudeofMPsinriversedimentsandthereleaseofMPsfromsoilfollowingextremerainevents.

ThemodelwasfinallyappliedtoanalyseviabilityofmanagementscenariosinCanadaforreducingecosystemexposuretoMPs.Thesescenariosweredrawnbasedoninputsandperspectivesfromfarmers,municipalitiesandthegovernmentsector,basedonamulti-actorresearchapproach.IntheSpanishscenario,themodelwasappliedtoevaluatepredictionperformanceandrunathoroughanalysisofparametersensitivityandlongterm,basin-scaleexposure.INCA-MPisavailableasanexecutablecomputerprogramwithafullgraphicalinterface.Inadditionitisdevelopedinaprogrammingenvironment(MOBIUS,developedbyNIVA)thatofferssimplifiedaccesstothepartofthemodelencodingthebiogeochemicalprocesses,facilitatingfuturescientificdevelopmentsofthemodelalsobynon-professionalprogrammers.

Stakeholderinteractiontookplaceunderamulti-actorapproach,wherebystakeholders(especiallyinthefarmingandwaterindustrysectors)servedbothasrecipientsofdisseminationandprovidersofinformationtoenableresearch.Routinemeetings(bothduringworkshopsandfacetofacemeetings)withstakeholderswerecarriedoutatbothnationalandinternationallevels.

Aspartofthisinteraction,astakeholderscopingstudywasconductedinSwedentodocumentknowledgeandattitudestowardsmicroplasticsinsludgeappliedtoagriculturalsoils.Thisanalysisincludedinterviewswith33actors(politicians,governmentworkers,waterindustryprofessionalsandresearchers).Itemergedthatthediscussion,policydebateandpositioningofstakeholdersinthecontextoftheproblemofplasticpollutioninbiosolidshasuntilnowbeenlargelybasedonfewsourcesanduncertaindata.The results from the scoping analysis shows that stakeholders do not believe they are sufficiently well informed about the issue,highlightingtheneedforfurtherresearchandcommunication.

StakeholdersfromCanadaandNorwayhavealsoprovidedtheirperspectivesontheusefulnessandeconomicviabilityofusingsewagesludge-derivedbiosolidforimprovingagriculturalperformance.Stakeholderssuggestedthattheuseofbiosolidsislikelytoincreaseinthefuture,asitembodiesacircularityapproach.Unfortunatley,thismaycollidewiththeneedtoprotecttheenvironmentfromplasticpollution.Hence,knowledgeandmodelsdeliveredbyIMPASSEwereusedtoframeandinvestigateeconomicallyviable,yetenvironmentallyandsociallysustainablemanagementofbiosolidsfromsewagesludge.

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Assessment of initial measures for MP pollution reductionTheevaluationofstrategiesforminimizingMPreleasetoagriculturalfieldsandfreshwaterenvironmentswasconductedconsideringperspectivesandinputsfromfarmersandwastewatermanagers.Stakeholdersidentifiedthatwithanincreasingpopulation(generatingexcesswaste),andasubsequentincreaseinfoodrequirements,the2%rateoflandapplicationofbiosolidswilllikelyincreaseovertime.TwopossiblemanagementscenarioswereidentifiedinrelationtotheCanadiancasestudyandsimulatedwiththeuseofthenewINCA-MPmodel.ThesewereconceivedtoassesspossibilityofachievingMPreleasesreductionunder:i)achangingclimateandii)changesinlanduse.

Withinthefirstscenario,IMPASSEresearcherswereaskedbystakeholderstoassesswhetherapplyingsludgeduringdryperiodswouldreducethereleaseofMPstowaterenvironments(apracticeadoptedforexample,forreducingrunoffoffertilizers).Modelsimulationsrevealedthatduringdrieryears,agriculturalsoilscanactasaMPaccumulator;however,sufficientlyhighrainfalleventscanmobilizetheMPsstoredevenyearsafterthebiosolidswerefirstapplied.Climate change will result in increased frequency of extreme rainfall events. Storage of MPs within all land uses is therefore likely to become less effective. Management solutions designed around meteorological events can therefore serve to delay, but not reduce, MP export to the environment.

InthesecondscenarioweassessedthatbiosolidsarenotcurrentlytheprimarysourceofMPstotheenvironment,althoughtheyareclearlyacriticalpathway.Stakeholdershaveindicatedafutureneedtoincreasebiosolidsapplicationrates,hencemodelscenarioswereruntoascertainthethresholdoflandarea(inpercentageofthecatchmentarea)atwhichbiosolidscanbeappliedbeforetheybecomethedominantsourcetowaterecosystems.Itwasfoundthatthethresholdis34%.Currentlyonly2%oftheagriculturallandistreatedinCanada.AsimilarfigureappliestoEurope.Hence,itwasrecommendedthateffectivepoliciesandinstrumentstoreduceplasticpollutionshouldinitiallyfocusonotherandmorerelevantsources.Inthis context, a comprehensive policy could indirectly lower the loads of MPs reaching wastewater at source, with benefits for biosolid quality and their applicability in farming.

AninitialeconomicviabilityanalysisperformedwithinIMPASSEsuggestedthatoptionsofincreasingtheuseofbiosolidsinagricultureareeconomicallyadvantageousforbothfarmersandmunicipalities(citizens).Thishowever,largelydependsonthepossibilityofreducingtheamountofMPsinbiosolidsatzero(orlowcost)andonthenon-verifiedassumptionsthatthecostofloosingenvironmentalcapitalandagriculturalperformanceduetotheimpactofMPsarenegligible.Atpresent,zero-costinstrumentsforpreventingplasticfromreachingwastewaterarenotknown,andagriculturalandenvironmentalexternalitiesofplasticpollutionarelittleunderstood.Researchintothesezero-costsolutionsforbiosolidsMPmanagementiscurrentlybeingfundedbytheCanadianFederalGovernment,thoughmoreresearchwillbeneededtoidentifyviablepoliciesandmanagementtoprotecttheenvironment from MPs and preserving circularity in the use of sewage sludge.

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Recommendations

We found that the application of biosolids from sewage sludge represents an important source of MPs to agricultural soils. Soils that received more biosolid treatments in the past exhibit higher levels of MPs, demonstrating progressively increasing pollution. Soil organisms underpinning essential ecological and agricultural functions interact with these MPs and experience sub-lethal health effects at realistic environmental concentrations.

The policy debate on the sewage sludge management should assimilate these findings as rapidly as possible. Continuous addition of MPs to agricultural soils will result, over time, in increasing pressure and risks for the soil ecosystem. The safety threshold to prevent abrupt and irreversible damage on soil ecological and agricultural services is unfortunately not known. Soil is a non-renewable resource and MP pollution in soil is likely irreversible.

The following recommendations are given::

• Regulation on sewage sludge use in agriculture should include legal thresholds for MPs.

• In order to safeguard circularity in the use of sewage sludge, cost-effective measures that can reduce or, better, remove MPs completely from sewage sludge should be strongly endorsed.

• Economic cost-benefit analysis of sewage sludge use in agriculture should include sound estimations of environmental externalities for both present day and future scenarios of MP contamination in soils and freshwater environments.

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Project background and objectives

Detailed Report of Results

Microplastics(MP)areincreasinglyseenasanenvironmentalproblemofglobalconcern.MPsinsoilshavelargelybeenoverlooked,whilealackofknowledgeoftheirimpactsonagriculturallandscapesandfreshwaterfromtheapplicationofsewagesludgehaspreventedthedefinitionofmeasuresforthesafeguardingofagricultureandtheenvironment.WastewaterTreatmentPlants(WWTPs)receivelargeamountsofMPsemittedfromhouseholds,industryandsurfacerun-offinurbanareas.MostoftheseMPsaccumulateinthesewagesludge.InmanycountriessludgefrommunicipalWWTPsisconvertedintobiosolidsandappliedtoagriculturalfieldsasasupplementtotraditionalfertilizers.CurrentlyMPsarenotintheregulatoryagendafortheuseofsludge.Knowledgeandawarenessoftheiramountsandimpactshavebeenmissing.IMPASSEwasoneofthefirstresearchprojectstodealwiththisissueinternationally.Itinvestigated,forthefirsttime,theloads,fluxesandpotentialecologicalimpactsofMPsinfarmingcasestudiesandconductedlaboratoryexperimentsinEuropeandCanada.

Exposure

Analytical method developmentAfirstimportanttaskofIMPASSEwastodevelopandvalidateamethodfortheanalysisofMPsinsoilandsludgesamples.Thiswasachievedthroughamethodbasedonbothmicroscopyandautomatedmicro-FourierTransformInfraRedSpectroscopy(the“goldenstandard”fortheanalysisofMPsinenvironmentalsamples).Aninitialstepofthesamplepreparationincludedremovalofinterferingnaturalorganicmatter.WeachievedremovalthroughbasicdigestionwithoutalteringthepropertiesofMPsinthesamples.

WeprovidedavalidatedmethodshowingrecoveriesofspikedreferenceMPs(fibersandfragments)rangingbetween70and98%.Thisresultedinaseminalpublicationwhichhasreceivedahighnumberofcitations.

AsetofMPreferencematerialswasdeveloped,andbatcheswereproducedtobeusedinvalidationexercisesandtoxicologicaltesting.MPreferencematerialsofenvironmentalrelevancewerenotavailableonthemarket.TheproductionofMPreferencematerialbatcheswaslaunchedforcommercialization.Theseproductshavebeendistributedinternationallytosupportqualityassuranceandcontrol,methodvalidationsandwatertreatmentefficiencyassessments.

Monitoring and MP budget assessmentsThenewvalidatedanalyticalmethodwasappliedtoanalysethesamplesfromscenarios(SpainandCanada),withcontrastingclimaticconditionswhereagriculturalsoilsaretreatedwithbiosolids.Wehaveconductedcomprehensivemonitoringcampaignsinagriculturalcatchmentscoveringfieldswithdifferenthistoryofbiosolidtreatmentandfieldsthatwerenevertreated(asareference).Wecollectedsamplesofsludge,sludge-basedfertilizers,agriculturalsoils,surfacerunoff,riversediments,streamwaterandwastewaterfromWWTPeffluents.

Inputs, levels and behavior of MPs from sewage sludge in agricultural soils and in downstream environments.

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ResultsindicatethatsludgesamplescontainedlargeamountsofMPs(AverageMPconcentrationsofbetween8,700MPand>14,000MPkgofdrysludge(Figure1))confirmingtheoreticalexpectationsthattheapplicationofbiosolidsrepresentsapredominantsourceofMPstoagriculturalsoils.TreatmentofbiosolidspriortouseinagricultureappearstoresultindifferentMPscontent,withde-wateringprocessduringstoragepossiblyprovidingameanstoreduceMPcontent.MPswerefoundincontrolsoilswheretherewasnorecordofbiosolidsapplication(Figure2),howeverMPconcentrationswereconsiderablyhigherinsoilswithahistoryofbiosolidsapplications,empiricallyconfirmingthatbiosolidtreatmentisapredominantsourceofMPstoagriculturalsoilsinthesefields(Figure2).Shortlyfollowingbiosolidsapplication,soilsexhibitedsignificantincreasesinMPlevels,predominantlyintheformofmicrofibers.ThemovementofMPsbetweensoillayersdifferedbetweensitesreflectingdifferentsoilconditionsandstructure.WhencomparingsoildatatotheMPmassappliedin2017,evidencefromallcasesshowedaconsiderablelossofMPsfromthesoilsinrelationtointenseprecipitations.InseveralinstancesagreaternumberofMPswerelostin2017thanwereapplied.Thisisinterpretedtobearesultofrunoffdrivenbytheintenseprecipitationrecordedduringthestudy.ThisevidenceindicatesthatsoilMPscanmobilizeandcontaminatefreshwaterecosystems.

In SpainthestudywasconductedintheHenaresRiverwatershed,whichislocatedintheupperTagusRiverBasin(CentralSpain).TheareaissubjectedtoacontinentalMediterraneanclimate,characterizedbyhotanddrysummersandmild-to-colddrywinters.Whiletheupperpartofthiswatershedismostlycharacterizedbyforestareasorextensiveagriculture,thelowerpartisinfluencedbyindustrialandurbanareasandfrequentmunicipalwastewaterdischarges.Here,westudiedMPconcentrationsinsoilsampleswithdifferenthistoriesofbiosolidapplications,inagriculturalrunoff,inriversedimentsandinstreamwater.Alsointhiscase,wastewatereffluentswereanalysedtoassessthecontributionofagriculturalrunoffcomparedtowastewatereffluentsinsupplyingMPstotheriver.MPswereidentifiedinallriversites,withwaterandsedimentconcentrationsrangingbetween1-227MP/Land0-2630MP/kgofsedimentdryweight,respectively.TheseMPswerepredominantlypolyethyleneandpolypropylenefragments.MPconcentrationsinriversedimentswerefoundtostronglydependonlanduseinthecatchment,withpollutionlevelsincreasingsignificantlydownstreamofurbanandindustrialareasandbeinglargerinthesedimentsinareaswithlowwaterflow.Weestimatedthataround10billionMPsaredischargedintotheHenareswatershedviawastewatereffluentsannually,constitutingabout50%ofthetotalMPsriveroutflow.Agriculturalrunoffmustthereforebearelativelysmallsourcebeingincluded(amongothersourcessuchasroadrunoff,atmosphericdriftanddeposition,

Sample kg of MPs per squared kilometer”

Sample MPconcentration(mg of plastic per liter of sample)

Soilwithbiosolidtreatment 37.7 Biosolids 6.1

Soilwithnohistoryofbio-solidtreatment

5.97 Agriculturalrunoff 7.1x10-3

Riverbedsediments 0.01 Urbanstormwaterflow 2.2X10-4

Wastewater treatment outflow

1.2X10-6

Water column 3.6x10-7

Figure1:ConcentrationofMPswithinstoredandfreshbiosolids,asmeasuredwithinhaulagecompaniesoperatingwithintheLakeSimcoeregion,Ontario

Figure2TotalMPconcentrationsinsoilspriorto2017biosolidsapplication.Field1,Field2,andField3werehistoricallytreatedwithsewagesludge-derivedbiosolidsatprogressivelyincreasingfrequencies

In Canada,MPmonitoringwasundertakeninthreecatchmentswithintheLakeSimcoeregionofOntariowitheitherasubstantialhistoryofbiosolidsapplicationsonagriculturallands,orwithnopreviousbiosolidapplication(control).Theregionischaracterizedbyaborealclimatewithwetandtemperatesummers.Samplesofagriculturalsoilweretakenbefore,duringandaftertheapplicationofbiosolidstoattemptadynamicmassbudgetofMPsatfieldlevel.SoilsamplesweretakenatmultiplesoildepthstoassessanyverticalmovementofMPs,andoverarangeoftransectsacrossdifferentslopeinclines.Table1summarizesresultsofMPmassesinsolidandliquidsamplescollectedintheCanadianstudy.

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Figure 3 Experimental set-up with field plots and runoff analysis conducted in the

Spanish case study

Figure 4MPs detected in soils of the Spanish case study, subjected to different sludge treatments, at the start and the end of the experiment reported by a) mean, min and max (error bars) concentration (MP kg-1) per experimental plot; b) polymer type observed at the start of the experiment (Start) and the end of the experiment (End) ; and c) mean, min and max (error bars) concentration (MP kg-1) according to different sample depth. Statistically significant differences compared to the control are indicated by asterisks (*), while significant differences between the start and the end of the experiment are indicated by asterisks in between dashes (-*-).

fragmentationoflitter,etc.)intheremaining50%.Ithastobehighlighted,however,thatunlikeinCanada,duringthestudyinSpainnomajorprecipitationeventsoccurredwhichmayhinderamorecompleteunderstandingoftheroleofagriculturalrunoffasasourceoffreshwaterMPpollution.

InordertodirectlyassesslevelsofMPsinagriculturalsoilsandthepossibilityoftheirreleasethroughrunoff,wesetthreeexperimentalplotsinthesamecatchmentequippedwithrunoffcollectiondevices(Figure3).Thetreatmentswereasfollows:(1)acontrolwithnosludgeapplication;(2)historicalsludgeapplicationfiveyearspriortothestartoftheexperiment;and(3)firstsludgeapplicationatthebeginningoftheexperiment.MPswereanalyzedinsoilbeforeandafterthesludgeapplicationandduringthestudyduration(3months).WealsomeasuredMPsincollectedrunoffsamples.LikeobservedinCanada,sludgeapplicationsignificantlyincreasedMPconcentrationsinsoils(Figure4).ThesoilMPconcentrationsremainedstableforoneyear.Surfacewaterrunoffundernormal(low-intensity)precipitationhadanegligibleinfluenceontheexportofMPsfromsoil,mobilizingonly0.02-0.04%oftheMPsadded.Thus,weconcludethat,undertheconditionsofthisstudy,agriculturalsoilsbehavedaslong-termaccumulatorsofMPs.HoweverevenbackgroundleachingofMPscancontribute,overtime,todeliverlargeamountsofMPstoaquaticecosystems.Despitethelowbackgroundrunoff,afterupscalingtotheareaofsoilstreatedwithsludgeindryenvironments(suchasSpainormoregenerallySouthernEurope)itisestimatedthattensoftonnesofMPsarereleasedeveryyeartoaquaticecosystemsfromfarmlands.Itissuggestedthatthefigurewillbeconsiderablyhigherinwetterenvironments.

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Figure5.Relationbetweenthe%oflong(4-24mm)polyestermicrofibersinsoilandnumberofenchytraeidswormsjuvenilesshowingastatisticallysignificant(p<0.05)reductionintheabilityofproducingoffspringsabove0.2%.

Figure6.Left,relationbetweenthe%ofpolyestermicrofibersdispensedinfoodandthenumberoffibersaccumulatedinearthwormsorfoundinegestedfaeces.Right.Picturesofegestedearthwormfaeces

Figure7.Relationbetweenthe%ofpolyestermicrofibersinsoil(left)anddispensedfood(right)andthenumberoffibersaccumulatedinenchytraeidswormsorfoundintheiregestedfaeces.

Figure8.Thesizedistributionoffibersextractedfromearthwormsandearthwormfaeces(lightblue)andfromthefoodofearthworm(darkblue).

Impacts on soil organismsPolyesterfibershadonlyslighteffectsonsoilinvertebrates.Survivalandreproductionofspringtailsandearthwormswerenotaffectedbypolyesterfibers,whilstenergyreservesoftheisopodswereslightlyaffectedwhenexposedtoshort(12mm–2.87mm)andlong(4–24mm)fibers.Reproductionofenchytraeidsalsodecreasedupto30%withincreasingfiberconcentration,butonlyforlongfibersinsoil(Figure5).Onlyafewfiberswereingestedbyenchytraeidsinthecaseoflongerfibers,whichsuggeststhatthefibersposedphysicalharmoutsidetheorganismratherthanhazardsduetofiberingestion.

Wormsandisopodsingestedpolyesterfiberstoo.Therateofingestionofearthwormsincreasedwithincreasingconcentrationinsoil(Figure6andFigure7),showingtheincreasedriskofsyntheticfiberstoenterthefoodwebwhenthenumberoffibersinthesoilishigh.Thefibersextractedfromtheearthwormsandfromearthwormfaeceswereshorterthantheonesextractedfromthespikedfood,whichsuggeststhatearthwormactivityinsoilcantransformpolyesterfiberstosmallersizesandthusincreasetheriskfortheiruptakeby(other)soilinvertebrates(Figure8).

Impacts

Alsotireparticles(i.e.crumbrubber,<180μm)hadonlyslighteffectsonsoilinvertebrates.Forenchytraeids,theslightdecreaseinreproductionwasnotdose-dependent.Onthecontrary,crumbrubberinducedchangesinglutathione-S-transferaseandcatalaseactivityinearthwormsatmoderateconcentrations,indicatingoxidativestress.Inspringtails,thehighesttestconcentrationofcrumbrubber(1.5%)decreasedthereproductionby38%andsurvivalby24%whenspikedinsoil,andsurvivalby38%whenspikedinfood.Acetylcholinesterase(AChE)activityofisopodswasdecreasedby65%atthehighesttestconcentrationinsoil,indicatingneurotoxicityofthematerial.Crumbrubbercontainedavarietyofpotentiallyharmfulsubstances.Zinc(21900mgkg-1)wasthedominanttraceelement,whilstthehighestconcentrationofthemeasuredorganiccompoundswasdetectedforbenzothiazole(89.2mgkg-1).Theseresultssuggestthatmicro-sizedparticlesfromtirewearcanaffectsoilinvertebratesatconcentrationsfoundatroadsides,whilstshort-termimpactsatconcentrationsfoundfurtherfromtheroadsidesareunlikely.

Effects of MPs were assessed on the health and viability of several freshwater and soil organisms considering realistic exposure scenarios.

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Decision support tool

Figure9.Upper:Daphnia magnaexposedfor21dto(A)control(B)0.015gfibers/L.Lowe:Reproductiondisplayedasmediannumberofoffspringperadult(±95%CI,n=10)after21dayofexposuretoincreasingfiberconcentrations.Thepercentageofsurvivingadultsis

Figure10.ReproductionrateofDaphnia magnadisplayedasmediannumberofoffspringperadult(±95%CI,n=10)after21dayofexposuretoincreasingcartirecrumbconcentration.Thepercentageofsurvivingadultsisshownabovetherespectivetreatment.

Figure11.EffectofMPsonthebioconcentrationofpesticides(Chlorpyrifos(left)andHexachlorobenzene(right)infish(Daniorerio),showingthepresenceofMPsloweredexposure.

TirecrumbrubberdecreasedthetoxicityofchlorpyrifosonthereproductionofthespringtailF. candida,whilstpolyesterfibersdidnotremarkablyaffectthechlorpyrifostoxicity.Thesefindingsindicatethattheeffectsofmicroplasticsonthetoxicityofthepesticidechlorpyrifosdependonthetypeandconcentrationofmicroplastics.

Furthermore,theeffectsonenergyreservesandimmuneresponseofthecrustaceanPorcellio scaberwasanalysedinrelationtoMPsizedistributionandshape.Theresultsshowthatafter3weeksofexposuretheoverallhazardoftestedmicroplasticstoP. scaberwaslow,howeverashiftinenergyallocationandinductionofimmuneresponsewereevident.Wealsoshowedthatmicroplasticsmayaltertheeffectsofotherpollutantswhichmaybepresentasmixtureswithmicroplastics.

Insummary,whiletheriskposedbyMPstosoilinvertebratesatenvironmnentallyrelevantlevelsarelow,theoccurrenceofsublethaleffectsevenatenvironmentallyrealisticconcentrationsimplythatprolongedexposurecanpotentiallyinducenegativeeffectsonsoilbiota.

Impacts on water organismsSinglespeciestoxicologicaltestswereperformedonzooplankton(Daphnia)andzoobenthos(Asellus, Hyalella, and Lumbriculus)toassessingestionandpotentialeffectsoftwotypesofMPs(fibresandtirecrumb)ondifferentshort-termandlong-termtoxicityendpoints.MPingestiondependedonMPtype,exposurepathway(waterorsediment)andfeedingstrategyorhabitatofthespecies.SurvivalandreproductionofzoobenthosspecieswerenotaffectedatthetestedMPconcentrations(upto0.15g/Lwateror2g/kgsediment).However,whileDaphniasurvivalwasalsonotaffectedduringshorttermexposure,reproductionandlong-termsurvivalsignificantlydecreasedinchronicexposuretestinthepresenceofbothMPtypes.InbothcasesconcentrationofMPsintherangeof0.015g/Lproducedsignificanteffects(Figure9and10).IncaseofFibersthiswasapparentlycausedbyimpededmovementduetoentanglementofDaphniainagglomeratesformedbyfibersandalgaeprovidedasfood(Figure9Upperpanel).

IncaseofcartirecrumbparticlesingestionbyDaphniaincreasedproportionatelytoexposureconcentration.ReproductionofDaphniawasnegativelyinfluencedbetween0.015and0.15g/L(Figure10).

A study on the effects and bioaccumulation of nano-sized plastic particles was also conducted with DaphniaExperimentswereconductedwiththreedifferentpolystyrenenanoplastics(20and100nmFITClabelled,and100nmRhodaminelabelled).Acuteimmobilisationtestsshowedthatsmallernanoplasticsdidnotcausesignificanteffects.UptakeofnanoplasticswasprovenforRhodaminelabellednanoplasticsusingfluorescence

microscopy.Fluorescencewasonlyobservedinthedigestivetractandtheoutsideofthecarapace,whichsuggeststhatthemajorityofparticleshavenotleftthedigestivetractandhavethereforenotenteredthecells.Eliminationofnanoplasticswasobserved3daysafterthetransfer of Daphniaintocleanwater.

Themodelisthefirstofitskind.Wecompletelyrecodedanexistingprototypeandaddedseveralnewfunctionsdescribingsize/shape/MPdensity-dependenttransportofMPs,aswellasfragmentationandheteroaggregationprocessesinsoilandwater.Themodelwasappliedtothedataofthecasestudiessuccessfully.Figure12andFigure13showresultsofmodelperformancefortheCanadianscenario.BothobservedandmodelleddatademonstratedsignificantlyhigherMPconcentrationsofagriculturalsoilswherebiosolidshadbeenpreviouslyapplied,comparedtoagriculturalsoilswithnohistoryofbiosolidsapplication.Themodelisavailableinanexecutableandfullygraphicallyinterfacedversion.Furthermore,itisalsoavailableinadevelopmentplatform(MOBIUS)operatingintheC++programminglanguagedevelopedbyNIVAthatenableseasymodificationofthemodelframebyfutureusers(evenwithlimitedtechnicalprogrammingskills).Thiswasconceivedtoenableusersintheenvironmentalresearchareatocontinuethedevelopmentofthemodelwithinandoutsidethisprojectconsortium.Finally,themodellingworkincludedtheprovisionofaninterfacewiththeprogramminglanguagePYTHONthatenablesrapidautomatizationforcontrollingtherunsofthemodelexecutableversiontofacilitate,forexample,calibration/validationexercisesanddevelopmentofsensitivityanalyses.ThemodelwasusedforthescenarioassessmentintheCanadiancasestudy.

We developed a new mathematical model of physical transport of MPs in the soil and freshwater at the watershed scale (INCA-MP).

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Figure12.ModelapplicationtotheCanadiancasestudy.Left:Geographicinformationsystemlayerdepictingcatchmentboundariesofthestudyarea(LakeSimcoeregion).Theyellowboundariesshowthecatchmentspecificallyselectedforthemodelsimulation.DotsrepresentsamplinglocationswhereMPmeasurementswereconductedinwaterorsediments.Right:INCA-MPdiscretizationoftherivernetwork.

Figure13.ModelapplicationtotheCanadiancasestudy.Upperpanelshowsthefitbetweenmodelled(redline)andobserved(bluedots)riverwaterdischarges(driveninthemodelbyanunderlyinghydrologicalmodule).Thelowerpanelshowspredicted(greenandredlines)vsobserved(blueandreddots,respectively)massesofMPsinthecatchmentsoilsovertime.(greenshowsresultsforsoilswithappliedsludgewhileredrepresentscontrolsoils).

Stakeholder interaction took place through a multi-actor approach, whereby stakeholders (especially in the farming and water industry sectors) served both as recipient of dissemination and providers of data.

Multi-Actor approach: Routine interaction took place at regional, national and international levels. Stakeholders in the farming, water industry and governance were asked to provide perspectives and ideas on practices that can lower MP pollution to soils and water environments. These inputs were used to assess management scenarios through the knowledge and decision support tools developed during IMPASSE. This activity involved in particular farmers and water industry in Canada, Norway and Sweden.

Stakeholder scoping analysis in Sweden: InDecember2020,IMPASSEattemptedafirstdocumentationofstakeholderknowledgeandattitudestowardsMPsinsludgeappliedtoagriculturalsoils.InSweden,weconductedinterviewswith33actorsincludingpoliticians,governmentworkers,waterindustryprofessionalsandresearchers.Ourresultssuggestthatstakeholdersdonotbelievetheyaresufficientlywellinformedabouttheissue,highlightingtheneedforfurtherresearchandcommunication.Resultswillbesubmittedtothepeer-reviewedliterature.

Final stakeholder conference:Weheldafinalvirtualstakeholderconferenceonthe2ndDecember2020,whichattracted60+registrantsfromSweden,Norway,Germany,Lithuania,SpainandCanada(www.impassesverige.weebly.com).Theeventfeaturedsummarypresentationsaboutresearchconductedduringtheprojectandapaneldiscussionaboutmicroplasticsinsludgeappliedtoagriculturalsoils.Inthiscontext,stakeholdersfromgovernance(SwedishEnvironmentalProtectionAgency)andWaterindustry(InternationalWaterAssociation)presentedtheirpositionanddata.Duringtheevent,anopendiscussionwasheldoncomparingperspectivesandpositionsinlightoftheresultsachievedbyIMPASSE.Inparticular,wefoundthatmostofthediscussionandpolicydebateonMPsinbiosolidscarriedoutamongsocietalactorsandgroupsofinterestswasuntilnowlargelybasedonlimitedanduncertainpreliminarydata.IMPASSEhasthereforeprovidedanewscientificbasistocontinuesuchadebatetowardseffectivepoliciesandinstrumentsforpreventingplasticsfromcontaminatingwastewaterresources.

Between June and July 2020weheldaseriesofvirtualmeetingswithstakeholdersincludingrepresentativesofplasticsandbioplasticsindustriesandinternationalgovernance.Inthesemeetings,weprovideddirectinformationonsomeofthekeyfindingsfromIMPASSEandobtainedadirectenrolmentofthesestakeholdersinanewresearchplanninginitiativethatresulted,inSeptember2020,inthesuccessfulapplicationtoaEuropeanCommissionH2020grant.TheprojectPAPILLONSfocusingonsources,

Stakeholders 2928

behaviourandimpactofplasticsinagriculturalsystemsistheresultofsuchaninitiative.PAPILLONSisbuiltusingtheIMPASSEconsortiumasacoreandfurtherexpandingitto20EuropeanandChineseresearchpartnersandalistof20Stakeholdersinthegovernance,industryandfarmingsectors.PAPILLONSisduetostartinMay2021.

European Chemical Agency (ECHA).IMPASSEresearchershaveundertakenimportantinteractionswithstakeholdersatEuropeanlevel.WewereinvitedbytheEuropeanChemicalAgency(ECHA)toattendtheworkshopontheRestrictionofIntentionally-AddedMicroplasticsunderREACHonthe30-31stMay2018.TherewegaveapresentationonIMPASSEtotheplenarygroup.WithinthatmeetingwepresentedandparticipatedinthediscussionintheAgriculturesub-group,providinganoverviewonexistingworksrelatedtoMPsinagriculturalsystems.

British Royal Society.WewereinvitedtocollaboratewiththeBritishRoyalSocietyduringthepreparationofasynthesisdocument(LivingLandscapes)onMPsforpolicymakersinUK.ThisdocumentwillfeedintotheUKgovernmentstrategyonMPs.

International Water Association (IWA) (Water Industry)WehaveactivelyparticipatedtotheIWAworldcongressinTokyoinSeptember2018.ThereweorganizedtwoworkshopsonMPs.Wepresentedourpreliminaryresultsandprovidedourperspectiveoverthefutureandneedsofresearchinthisfield.

A series of possible practices for reducing MP addition to soils were proposed by farmer and wastewater stakeholders and assessed by IMPASSE

1.MP reduction under a changing climate:ScenarioswererunusingtheINCA-MPmodeltotestthehypothesisthatstorageofMPsinsoilsoccursindryeryears.The2017precipitationwasreducedby50%,andthemodelre-runforthe2017period.Relativestorageandtransportamountswerecomparedforallland-uses,betweenthe‘wetyear’(observed2017rainfallscenario),andthedryyear(50%precipitationscenario)(Figure14).

Figure14:ProportionofMPsstoredandtransportedduringadryyear,assessedthroughanINCA-MPmodelapplication

Themeteorologicalsimulationrevealedthatduringdrieryears,agriculturalsoilscanactaseffectivestores;Thisexplainshowthe‘residual’MPsoilstoresaregenerated.WhiletheabilityofsoilstostoreMPsmightatfirstappeartobeapotentialmanagementsolution,sufficientlyhighrainfalleventssubsequentlymobilizethesestores,evenyearsafterthebiosolidswerefirstapplied.Climatechangewillresultinanincreasedfrequencyofextremerainfallevents.StorageofMPswithinallland-usesisthereforelikelytobecomelesseffective.Managementsolutionsdesignedaroundmeteorologicalevents(e.g.applicationofbiosolidsindryperiods)willserveonlytodelay,butnotreduce,MPexporttotheenvironment.

Scenario assesment

Stakeholdershaveidentifiedthatwithincreasingpopulation(generatingexcesswaste),andasubsequentincreaseinfoodrequirements,the2%rateoflandapplicationofbiosolidswilllikelyincreaseovertime.Twopossiblemanagementscenarioswereidentifiedanddisclosedtostakeholdersduringthefinalstakeholdermeeting.

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2.Changes in MP inputs with changes in land-useAlthoughbiosolidsarenotcurrentlytheprimarysourceofMPstotheenvironment,theyareclearlyacriticalpathway.StakeholdersinCanadahaveindicatedafutureneedtoincreasebiosolidsapplicationrates,hencemodelscenarioswereruntoascertainthethresholdoflandarea(in%ofthecatchmentarea)atwhichbiosolidscanbeappliedbeforetheybecomethedominantsourceofMPs.Atacriticalthresholdof34%ofagriculturalland,biosolidsareestimatedtobecomethedominantsourceofMPstothecatchment.Currentlyonly2%oftheagriculturallandistreatedwithbiosolids.Ourresultshighlightedthatgiventhecurrentrelativelylowratesofbiosolidapplicationstofields,effectivepoliciesforprotectingwaterecosystemsfromMPsshouldinitiallyfocusonreducingsourcesotherthanbiosolids,whilemeasurestoreducereleasesofMPsatsourcesandtheirinputtowastewatertreatmentplantswillbenecessaryinthefuturetoguaranteecircularityintheuseofsludge.

Economic effectiveness of identified MP management strategies.EconomiceffectivenessofidentifiedmanagementstrategieswasanalyzedconsideringtheCanadianscenario(scaledtoOntarioProvince).Suchanalysisisboundwithinthecontestofthecoststhatcouldbeaccuratelyestimatedgivencurrentknowledgeanddata.

Theeconomicefficiencyoffourmanagementoptionswereexplored,baseduponobservationsandinputfromstakeholders(Figure14).

• Option1:toreducethe%ofbiosolidsappliedandreducelandcoverageto1%;• Option2:tomaintaincurrentcoverage,andapplybiosolidsduringdrierperiods;• Option3:toincreasethe%ofbiosolidsapplied,andincreaselandcoverageto4%(assumingMPswereremoved

frombiosolidsatnetzerocost);• Option4:toincreasethe%ofbiosolidsapplied,andincreaselandcoverageto5%(assumingMPswereremoved

frombiosolidsatnetzerocost).

Hence, this analysis does not include the assessment of the possible negative economic impacts posed by plastic pollution onto environmental or agricultural ecological services. These externalities cannot be estimated based on the knowledge produced within this novel area of research. Resolving this gap was beyond the scope of this project and will be a core scientific challenge for the incoming years.

Figure15:Estimatedchangeinindustryvalue($MillionCAD)undereachmanagementoptionevaluated

Inallthesescenarios,itwasassumedthatzerocostmethodstoreduceMPsfrombiosolidscouldbeachieved.Options1and2maintainingorreducingratesofsludgeapplicationappeartobeeconomicallyinefficient.TheyenableminorsavingsintransportcoststotheWWTPindustry,andcauseincreasedexpenditureforfarmersduetopurchasingofchemicalfertilisersasreplacement.Economically,thegreatestvalueisinincreasingtherateofagriculturalapplicationofbiosolids.Byassociationthisrequiresincreasingtheproportionoflandtowhichtheyareapplied.Becausescenarios4and5arebotheconomicallyconvenientandassimilatecircularity-thinking,theywillmostlikelybecorepillarsofpolicyaddressesandmanagementinthecomingyears.Unfortunately,reducingtheamountofMPsinbiosolidsmaynotbecostfree.RestrictionsofMPuseinpersonalcareproducts(arelativelylowcostmeasure,affectinghowever,assetsintheindustrialmanufacturingsector)onlyresultinapartialreductionofplasticinputstothesewage.Similarly,passivebiosolidtreatment(e.g.dewatering)canpossiblyremoveonlyafractionoftheMPs.SolutionsthatwillenableabulkremovalofMPsfrombiosolidsincludeincinerationwithrecoveryofmineralnutrients,orinfrastructuralsolutionstolimittransferofMPfromlaundryeffluents(carryingmicrofibers)orurbanrunoff.ItisthereforeunlikelythatMPscouldbecompletelyremovedfrombiosolidsatzero-costs.Amoredetailedanalysisremainsforfuturestudies,wherealsopossiblecostsoflongtermagriculturalandenvironmentalimpactsofMPsshouldbeestimatedandassimilated.

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Conclusions & Recommendations

• BiosolidsfromsewagesludgearevectorsoflargeamountsofMPs.Itisestimatedthatinmassunits,drybiosolidscontainonaveragebetween400and800mgofMPsperkgofdryweight,prevalentlyintheformoffibersandfragments.ItisimportanttonotethatthesefiguresarebasedonexperimentalassessmentsperformedonbiosolidsproducedinasemiruralcontextandanalyzedwithamethodvalidatedforMPswithaminimumsizeof50micrometer(intheirlargerdimension).Theadoptedmethodisnotoptimizedandvalidatedtodetectblackrubberparticles(e.g.,fromcartiredebris).Becauseofthis,thefiguresreportedherearetobeconsideredasunderestimationsofthereallevelofMPcontaminationinbiosolids.

• ApplicationofbiosolidsfromsewagesludgeisadominantsourceofMPstotreatedagriculturalsoils.

• Soilswithlongerhistoryoftreatmentswithbiosolidsaremorecontaminatedthansoilswithonlyrecenttreatmentsorsoilsthatwerenevertreated.Henceagriculturalsoilsbehaveaslong-termaccumulatorsofMPs.

• MPsfromsoilstreatedwithbiosolidsfromsewagesludgecanundergoremobilizationdrivenbywaterrunoff.Whilebaselinelow-intensityprecipitationappearstomobilizeonlyaminimalfractionofMPsfromthesoil,ourevidencesuggeststhatextremeprecipitationeventscaninsteadreleasealargeamountofMPstodownstreamenvironments.

• Indryenvironments,inyearswithoutflooding,MPsleachedbyagriculturalsoilsarelikelytorepresentaminorfractionofthetotalloadofMPsreachingrivers(fromallothersources).Whilethiscouldnotbeassesseddirectlyinexperimentalterms,amassbalanceanalysisatthefieldscalehighlightedthatduringflooding,MPreleasesfromtreatedagriculturalsoilsmayrepresentanimportantsourceofMPstodownstreamwaterecosystems.

• Atenvironmentallyrelevantconcentrations,effectsofMPsonsoilandwatermacroinvertebratesandzooplanktonwereverysmall,butinsomecasesdetectableandsignificant.OrganismswereobservedtointeractwithMPsintheirenvironment.MPswereingestedorentrainedontheexternalpartsoftheorganisms’body.

IMPASSEprovidedseminalknowledgeoftheroleofsewagesludgeapplicationtoagriculturalsoilassourceofMPs.TheprojecthasprovidedseminaldataontheeffectsofselectedtypesofMPs(commoninsludge)onabroadrangeofsoilandwaterorganisms.Mainconclusionsare:

• Whilesurvivaleffectswerenegligible,arangeofsublethaleffectsonreproduction,massallocation,energystorageandbiomarkerresponseslinkedtotheimmunesystemwereobservedinsoilorganismsatconcentrationsrepresentativeofhighlycontaminatedsoils(possibleinrealenvironmentalconditions).Uponingestion,earthwormswerefoundtomodifytheproperties(i.e.,length)ofmicrofibers,indicatingthatorganismscanaffectbehaviorandbioavailabilityofMPs.

• WhiletheacuteriskposedbyMPstosoilandwaterinvertebratesatenvironmentallyrelevantlevelsislow,prolongedexposureholdsthepotentialtonegativelyaffectabroadspectrumoforganismswithdifferentecologyandfunctions,someofwhicharekeyforsustainingagriculture.

• Co-occurrenceofMPsandorganiccontaminantsinsoilandwatercanaffectthebioconcentrationofthesecontaminantsinbiota.Inexperimentswithfish,weobservedthatMPscanlowerthebioconcentrationofpollutants.

• Afterdialoguingwithstakeholdersinthefarmingandwastewaterindustrysector,itemergedtheyexpectthattheuseofbiosolidsinagriculturewillincreaseduetotheneedsofenablingacost-effectivedisposalofproducedWWTPsolidwaste,increasingeconomicefficiencyofagriculturalproduction(e.g.,byreducingtheuseofartificialfertilizers),andacknowledgingadoptionofcircularityinagricultureandwastemanagement.Itemergedhowever,thattheunderstandingandtheadoptednarrativesamongsttheseactorswithregardstoMPcontaminationandtheirecologicalandagriculturalimpactswere(necessarilyatthisstage)basedoninsufficientdata.

Our recommendation are the following;

• ThepolicydebateonsewagesludgemanagementshouldassimilatethenewdataandknowledgeemergingfromIMPASSEandotherresearchinitiativesasrapidlyaspossible.

• RegulationonsewagesludgeuseinagricultureshouldincludelegalthresholdsforMPs.

• AsMPsarenoteasilydissipatedbysoilsandpersistintheenvironment,regulationshouldacknowledgethatcontinuousadditionofMPstoagriculturalsoilswillresultinincreasingpressureandrisktosoilorganisms.

Soilisanon-renewableresourceandMPpollutioninsoilislikelyirreversible.Undernaturalprocesses,MPscanonlybereleasedfromsoilsatthecostofcontaminatingdownstreamenvironments.Undercurrenttreatmentscenariosorpossiblefuturescenarioswithincreaseduseofbiosolidsfromsewagesludgeinagriculture,pollutionlevelswilltendtoincrease.Regulatorsshouldconsiderthatwhilesublethaleffectsonsoilbiotaarepossiblealreadyatpresentdaylevels(incaseofhighlypollutedecosystems),thesafetythresholdtopreventabruptandirreversibledamageofMPsonsoilecologicalandagriculturalservicesisnotknown.

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PublicationsWe furthermore recommend that:

• inordertosafeguardcircularityintheuseofsewagesludge,policies,managementapproachesandtechnologiesthatcost-effectivelyreduceor,better,removecompletelyMPsfromsewagesludgearestronglyendorsed.

• economiccost-benefitsanalysisofsewagesludgeuseinagricultureshouldincludesoundestimationsofenvironmentalexternalitiesforbothpresentdayandfuturescenariosofMPcontaminationinsoilsandfreshwaterecosystems.

Published1. Dolar,A.,Selonen,S.,vanGestel,C.A.M.,Perc,V.,Drobne,D.,JemecKokalj,A.2021.Microplastics,chlorpyrifosandtheirmixturesmodulateimmuneprocessesinthe

terrestrialcrustaceanPorcellioscaber.ScienceoftheTotalEnvironment772,144900.https://doi.org/10.1016/j.scitotenv.2020.144900

2. Crossman,J.,Hurley,R.R*.,Futter,M.,andNizzetto,L.2020.Transferandtransportofmicroplasticsfrombiosolidstoagriculturalsoilsandthewiderenvironment.ScienceoftheTotalEnvironment724:138334.https://www.sciencedirect.com/science/article/pii/S0048969720318477

3. Selonen,S.,Dolar,A.,JemecKokalj,A.,Skalar,T.,ParramonDolcet,L.,Hurley,R.,vanGestel,C.A.M.2020.Exploringtheimpactsofplasticsinsoil–Theeffectsofpolyestertextilefibersonsoilinvertebrates.ScienceoftheTotalEnvironment700:134451.https://doi.org/10.1016/j.scitotenv.2019.134451

4. Galafassi,S.,Nizzetto,L.,Volta,P.,Plasticsources:Asurveyacrossscientificandgreyliteraturefortheirinventoryandrelativecontributiontomicroplasticspollutioninnaturalenvironments,withanemphasisonsurfacewater,2019,ScienceoftheTotalEnvironment693,133499.https://www.sciencedirect.com/science/article/piiS0048969719334199?via%3Dihub

5. Schell,T.,Rico,A.,Vighi,M.,Occurrence,fateandfluxesofplasticsandmicroplasticsinterrestrialandfreshwaterecosystems.2019ReviewsofEnvironmentalContaminationandToxicology,DOI10.1007/398_2019_40.https://link.springer.com/chapter/10.1007%2F398_2019_40

6. DeSá,LC,MOliveira,FRibeiro,TLRocha,MNFutter,2018.Studiesoftheeffectsofmicroplasticsonaquaticorganisms:whatdoweknowandwhereshouldwefocusoureffortsinthefuture?.Scienceofthetotalenvironment,645,pp.1029-1039.https://www.sciencedirect.com/science/article/pii/S0048969718326998

7. Hurley,R.R.LusherA.L,Olsen,M.,Nizzetto,L.ValidationofaMethodforExtractingMicroplasticsfromComplex,Organic-Rich,EnvironmentalMatrices,2018,Environ.Sci.Technol.,2018,52(13),pp7409–7417https://pubs.acs.org/doi/10.1021/acs.est.8b01517

8. Hurley,R.R,Nizzetto,L.Fateandoccurrenceofmicro(nano)plasticsinsoils:Knowledgegapsandpossiblerisks,2018,CurrentOpinioninEnvironmentalScience&Health,Pages6-11https://www.sciencedirect.com/science/article/pii/S2468584417300466VanGestel,C.A.M&Selonen,S.2018.Ecotoxicologicaleffectsofmicroplasticsinsoil:New

9. researchthemesshouldnotignorebasicrulesandtheories.CommentsonthepaperbyZhuetal.(2018)“Exposureofsoilcollembolanstomicroplasticsperturbstheirgutmicrobiotaandalterstheirisotopiccomposition”.SoilBiologyandBiochemistry116:302-310.https://doi.org/10.1016/j.soilbio.2018.05.032

10. Crossman,J.,andWeisener,C(eds).2020.ContaminantsoftheGreatLakesHandbookofEnvironmentalChemistryDOI10.10.1007/698_2020_592.https://www.springer.com/gp/book/9783030578732

In review

10. Baho,D,MBundschuh,MNFutter,underreview.Microplasticsinterrestrialecosystems:movingbeyondthestateofthearttominimizetheriskofecologicalsurprise.GlobalChangeBiology

11. Schell,T.,Hurley,R.,Buenaventura,N.,Ablanque,P.V.M.,Nizzetto,L.,Rico,A.,Vighi,M.,Fateofmicroplasticsinagriculturalsoilsamendedwithsewagesludge:Theimportanceofsurfacewaterrunoffasanenvironmentalpathway.SubmittedtoEnvironmentalScience&Technology

12. Schell,T.,Hurley,R.,Nizzetto,L.,Rico,A.,Vighi,M.,Spatio-temporaldistributionofmicroplasticsinaMediterraneanwatershed:theimportanceofwastewaterasanenvironmentalpathway,SubmittedtoEnvironmentInternational

13. Selonen,S.,Dolar,A.,JemecKokalj,A.,Sackey,L.N.A.,Skalar,T.,CruzFernandes,V.,Rede,D.,Delerue-Matos,C.,Hurley,R.,Nizzetto,L.,VanGestel,C.A.M.Exploringthe

impactsofmicroplasticsandassociatedchemicalsintheterrestrialenvironment–exposureofsoilinvertebratestotireparticles.(submitted)

In preperation14. Lavoy,M*.,andCrossman,J.Insubmission.AnovelmethodfororganicmatterremovalfromsoilsandwastewatersamplescontainingmicroplasticsJournalof

EnvironmentalPollution

15. Norling,M.,Rico,A.,Schell,T.,Crossman,J.,Futter,M.,Nizzetto,L.,ConstraininguncertaintiesinMPfateandtransportincatchment,(Inpreparation)

16. Schell,T.,Rico,A.,Cherta,L.,Dafouz,R.,Giacchini,R.,Vighi,M.,Bioconcentrationoforganiccontaminantsinfishinpresenceofmicroplastics:isthe“Trojanhorse”effectmatterofconcern?(inpreparation)

17. Schell,T.,Martinez,S.,Dafouz,R.,Hurley,R.,Rico,A.,Vighi,M.,Acuteandchroniceffectsofsyntheticfibersandtirefragmentsforfreshwaterinvertebrates(inpreparation)

18. Žilinskaitė,E,DCollentine,MNFutter.inprep.Swedishstakeholderperspectivesonmicroplastics(fromsludge)toagriculturalland

19. Materić,D,MPeacock,JDean,MFutter,TMaximov,FMoldan,TRöckmann,RHolzinger.inprep.Localandregionalsourcesdrivethedepositionofnanoplasticsinlakesandstreams

20. Selonen,S.,JemecKokalj,A.,DolarA.,Drobne,D.,VanGestel,C.A.M.etal.Microplasticsaspossiblemodifiersofpesticideeffectsinsoil–theeffectsofpolyesterfibers

andtirewearparticlesonthetoxicityofchlorpyrifostosoilinvertebrates

List of conference presentations

1. Baho,D.,Evidenceforharmfuleffectsofmicroplasticsinsoil,SwedishUniversityofAgriculturalSciences,IMPASSEFinalstakeholdermeeting,Virtualworkshop2020.

2. Collentine,D.,Theprecautionaryprincipleandmicroplasticsinsludgespreadonagriculturalsoils,SwedishUniversityofAgriculturalSciences,IMPASSEFinalstakeholdermeeting,Virtualworkshop2020.

3. Žilinskaitė,E.,Swedishstakeholdersperspectivesonmicroplastics,SwedishUniversityofAgriculturalSciences,IMPASSEFinalstakeholdermeeting,Virtualworkshop2020.

4. Crossman,J.,andM.N.Futter.Transferofmicroplasticsthroughagriculturalsoils.Noregrets?Theaccumulationofmicroplasticsinagriculturalsoil.SwedishUniversityofAgriculturalSciences,IMPASSEFinalstakeholdermeeting,Virtualworkshop2020.

5. Schell,T.,Dafouz,R.,Rico,A.,Vighi,M.AcuteandchroniceffectsoftireparticlesandmicrofibersonDaphniamagna,30thSETACEuropeAnnualMeeting.Dublin,May2020

6. Rico,A.,Schell,T.,Hurley,R.,Nizzetto,L.,Vighi,M.,Fateofmicroplasticsinagriculturalsoilsamendedwithsewagesludge,30thSETACEuropeAnnualMeeting.Dublin,May2020

7. Crossman,J.,Hurley,R*.,Nizzetto,L.,andFutter,M.N.Microplasticsinbiosolidsandagriculturalsoils.SETACNorthAmerica,Toronto,2019.

8. Koestel,J,EBäckström,ALehoux,NGottselig,MNFutter.2019.3-dimensionalimagingofnanoplastictransportthroughasandcolumnusingmagneticresonanceimaging.PosterpresentationatSETACHelsinkimeeting,.AbstractM0281,May2019

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9. Lavoy,M*.,andCrossman,J.Transportandfateofmicroplasticswithinwastewatertreatmentsystems.InternationalAssociationofGreatLakesResearch.Brockport,NY,USA.2019.

10. Nizzetto,L,MNorling,RHurley,JCrossman,ARico,JLJLedesma,TCSchell,MNFutter.2019.Acomprehensivemodelofmacro-,micro-andnano-plasticfateandtransportincatchmentsoilsandsurfacewatersPosterpresentation256atSETACTorontomeeting,November2019

11. Schell,T.,Martinez,S.,Dafouz,R.,Hurley,R.,Rico,A.,Vighi,M.,Effectsofmicrofibersandtyredebrisonfreshwaterinvertebrates,29thSETACEuropeAnnualMeeting.Helsinki,May2019

12. Schell,T.,Hurley,R.,Rico,A.,Nizzetto,L.,Vighi,M.,Assessingtherelevanceofwastewaterandrunoffasmicroplasticsourcesforaquaticenvironments:AcasestudyincentralSpain,29thSETACEuropeAnnualMeeting.Helsinki,May2019

13. Schell,T.,Martinez,S.,Quesada,M.M.,Dafouz,R.,Rico,A.,Vighi,M.,Ingestionandimpactsoftireparticlesandsyntheticfibersonfreshwaterinvertebrates,SETACNorthAmerica40thAnnualMeeting.November2019

14. Crossman,J.,Futter,M.N.,Hurley,R*.,Vighi,M.,Schell,T.,Bundschuh,M.,andNizzetto,L.Impactsofmicroplasticsinfarmedsoilsandstreamecosystems.InternationalAssociationofGreatLakesResearch,2018.

15. Futter,M.N,Crossman,J.,Ledesma,L.J.,Russo,V.E.,Nizzetto,L.INCA-MP:Alandscapescaleframeworkforsimulatingmicroplasticfateandtransportinsoilsandsurfacewaters.PosterpresentationatSETACRomemeeting,May2018

16. Lavoy,M*.,Masih,D*.,andCrossman,J.Microplastics:emergingcontaminantsinfreshwaterandwastewaterWorldWaterDay,2018.

17. Hurley,R.Luscher,A.,Olsen,M,Nizzetto,L.,AnalysisandQA/QCofmicroplasticsinsoil,sludge,andsedimentsamples.Quasimemeworkshop,November2018

18. Hurley,R.,Lusher,A.,Olsen,M.,Nizzetto,L.,Soilandsludge:atimeandcosteffectivemethodforextractingmicroplasticsfromcomplex,organic-richenvironmentalsamples,28thSETACEuropeAnnualMeeting,Rome,May2018.

19. Hurley,R.,Nizzetto,L.,Microplasticdynamicsinagriculturalsoilsystems:firstresultsfromaninternationalprojects,EmCon2018,Conference,Oslo,June2018

20. Hurley,R*.Schell,T.,Crossman,J.,Rico,A.,Nawrocki,B.,Lavoy,M.,Vighi,M,Nizzetto,l.,Microplasticsdynamicsinagriculturalsystems:InsightsfromSpanishandCanadiancasestudies,MICRO2018,Lanzarote,November2018.

21. Hurley,R.Schell,T.,Rico,A.,Vighi,M.Runoffofmicroplasticsfromagriculturalsoil:astudyinasemi-aridarea,28thSETACEuropeAnnualMeeting.Rome,May2018

22. Rico,A.,EffectsOfMicroplasticsInFreshwaterAndSoilEcosystems,SpecialSession-IWAWorldWaterCongress,Tokio,September2018

23. Schell,T.,Effectsofmicroplasticsforfreshwaterandsoilorganisms,IWAWorldWaterCongress,Tokio,September2018

24. Schell,T.,Hurley,R.,Rico,A.,Nizzetto,L.,Vighi,M.,EnvironmentalLoadsandFateofMicroplasticsintheHenaresWatershed,CentralSpain.IWAWorldWaterCongress,Tokio,September2018

25. Schell,T.Hurley,R.Rico,A.,Vighi,M.Microplasticsinwastewaterandfreshwater:aSpanishCaseStudy,28thSETACEuropeAnnualMeeting.Rome,May2018

26. SelonenS.,ParramonDolcetL.,JemecKokaljA.,DolarA.,HurleyR.,vanGestelC.A.M.2018:Syntheticfibersaffectingsoilanimals–Soilanimalsaffectingsyntheticfibers.PlatformpresentationinMICRO2018Meeting,19-23November2018,Arrecife,Lanzarote,Spain.

27. SelonenS.,vanGestelC.A.M.2018:Synthetictextilefibersendupinagriculturalsoils–Canthesemicroplasticsposeathreatonsoilorganisms?PosterspotlightpresentationinSETACEuropeAnnualMeeting,13-17May2018,Rome,Italy.

28. Futter,M.N.IMPASSE(ImpactsofMicroPlasticsinAgroSystemsandStreamEnvironments).InternationalWaterAssociationMeeting,Malmö,Sweden,Nov7,2017.

1. Petersen,K.,2020,Microplasticsinfarmsoils:Agrowingconcern,https://www.ehn.org/plastic-in-farm-soil-and-food-2647384684.html

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3. Petersen,K.,2020Farmsshow‘irreversiblecontamination’ofsoil,https://www.greenbiz.com/article/farms-show-irreversible-contamination-soil

4. CBCnews:2020,CBCWindsorNewsinterview:Canada-wideStrategyonZeroPlasticWaste:researchtoremoveMicroplasticsfrombiosolids

5. Gibbens,S.2018.‘Alarming’levelofmicroplasticsfoundinamajorU.S.river.NationalGeographic.https://www.nationalgeographic.com/environment/article/alarming-levelmicroplastics-found-tennessee-river

6. Thompson,A.,2018.Earthhasahiddenplasticproblem–scientistsarehuntingitdown.ScientificAmericanhttps://www.scientificamerican.com/article/earth-has-a-hidden-plasticproblem-mdash-scientists-are-hunting-it-down/

7. IHEARTRADIO.2018:LiveRadioInterview:ClimateChangeImpacts

8. ScientificAmerican–PressInterviewhttps://www.scientificamerican.com/article/earthhas-a-hidden-plastic-problem-mdash-scientists-are-hunting-it-down/

9. ECHAnewsletterVideointerviewhttps://newsletter.echa.europa.eu/home/-/newsletter/entry/tracking-microplastics-from-sewage-sludge-to-the-oceans

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11. Magazine”TekniikkajaTalous”,Finland.Interviewhttps://www.tekniikkatalous.fi/tiede/tutkimus/suomalaistutkija-selvittaa-mita-mikromuovit-tekevatmaaperassa-ja-elioissa-tiedamme-niin-vahan-etta-pitaa-lahtea-liikkeelle-perusasioista-6704136

List of popular science articles

About the consortiumProject coordinatorTheNorwegianInstituteforWaterResearchisaleadingenvironmentalresearchcentreinNorwaywithaninternationallyorientedresearchprogramme.NIVAhasrunresearchanddevelopmentprojectsinover70countries.Since2016NIVAhaspioneeredresearchonfateandtoxicityofmicroandnanoplastics,hostingstate-of-the-artfacilitiesandinfrastructuresforanalyses,monitoring,ecotoxicitytestsandmodellingoffateanddistribution.

Contact:Dr Luca [email protected]

IMDEAWaterbelongstotheIMDEAnetworkofresearchinstitutesofthecommunityofMadridandconductsresearchonallaspectsofintegratedsoilandwatermanagementandenvironmentalsustainability.Since2017IMDEAWaterhasbeeninvolvedinseveralresearchactivitiesaimedatassessingthefateandeffectsofmicroplasticsinagriculturalandsurfacewaterenvironments.

Contact:[email protected]

TheDepartmentofBiologyoftheBiotechnicalFacultyatUniversityofLjubljanacarriesoutinternationalleveleducationandresearchactivitiesondifferentareasofnaturalresourcesprotectionandmanagement(soil,physicalspace,flora,faunaandwater).Since2015thedepartmentconductsresearchonmicroandnanoplastichazardinaquaticandterrestrialenvironments.


ThedepartmentofAquaticSciencesandAssessmentattheSwedishUniversityofAgricultureinUppsalafocusesonresearchonenvironmentalpollutants,biodiversity,andecosystemservices.Since2016thegrouphasconductedseminalresearchonfate,distributionandimpactofmicroandnanoplasticsinterrestrialandfreshwaterenvironments.


TheDepartmentofEcologicalScienceoftheFacultyofScienceatVrijeUniversiteitAmsterdamisattheinternationalforefrontofsoilecologicalandecotoxicologicalresearchfocusingontheeffectsofchemicalandabioticstressors(incl.climatechange)atdifferentlevelsofbiologicalorganization.


TheDepartmentofEarthandEnvironmentalSciencesatWindsorUniversitydevelopworldclassresearchongeofluids,geochemistry,andenvironmentalgeoscience.Since2016Thedepartmenthasanactiveresearchprogrammeonmicroplasticssourcesandtransportinterrestrialandfreshwaterenvironments.


Additional partners

TheFinnishEnvironmentInstitute(SYKE)istheleadingFinnishinstituteworkingonthebroaderareaofenvironmentalresearch.SYKEhasastrongbackgroundinMPsresearch,bothineffectsassessment,analytics,andmonitoring.Theresearchinterestsalsoincludevarioustopicsrelatedtoplasticsincirculareconomy


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Contributors to IMPASSE research tasks:

Visual concept and graphic editing of the document: CBMedia&PublishingAS

Sognsveien6bOslo,0451NorwayOrg:912004422

cbmediapublishing.com


ThisdocumenthasbeenpreparedandpublishedbyNIVAonbehalfoftheIMPASSEconsortium.01/05/2021

Gaustadallé[email protected]


TitleIMPASSE–Impactsofmicroplasticinagrosystemsandstreamenvironments

Seriel number7632-2021

Jill Crossman (PI), Mitchell Hall1.05.2021

Author(s)Nizzetto,Luca;Rico,Andreu(IMDEA);VanGestel,Kees(VU);Selonen,Salla(SYKE);Crossman,Jill(WindsorUniv.);Futter,Martyn(SLU);JemecKokalj,Anita(LjubljanaUniv.)

Topic GroupContaminants

DistributionOpen

Geographical area World

Pages42

Client(s)WaterChallengesforaChangingWorldJointPro-grammeInitiative(WaterJPI)JointProgrammingInitiativeonAgriculture,FoodSecurityandClimateChange(FACCEJPI)

Client’s reference7632-2021

Printed NIVAProjectnumber17160

Summary Wefoundthattheapplicationofbiosolidsfromsewagesludgerepresentsanimportantsourceofmicroplastics(MP)toagriculturalsoils.SoilsthatreceivedmorebiosolidtreatmentsinthepastexhibithigherlevelsofMPs,demonstratingprogressivelyincreasingpollution.SoilorganismsunderpinningimportantecologicalandagriculturalfunctionsinteractwiththeseMPsexperiencingsublethalhealtheffectsatrealisticenvironmentalconcentrations.Soilisanon-renewableresourceandsoilMPpollutionisirreversible.Toenablesustainableandcircularuseofsewagesludge,measuresthatpreventMPsaccumulatinginit,orthatremovethempriortousearenecessary”.

Four keywords

• Microplastics• Agriculture• SewageSludge• Soil

Fire emneord

• Mikroplast• Jorbruk• Kloakkslam• Kord

Main OfficeGaustadalléen21NO-0349Oslo,NorwayPhone(47)22185100

NIVA Region EastSandvikaveien59NO-2312Ottestad,NorwayPhone(47)22185100

NIVA Region SouthJonLilletunsvei3NO-4879Grimstad,NorwayPhone(47)22185100

NIVA Region WestThormøhlensgate53DNO-5006BergenNorwayPhone(47)22185100

NIVA DenmarkNjalsgade76,4thfloorDK2300CopenhagenS,DenmarkPhone(45)39179733

Copyrights

ThisreportisqualityassuredinaccordancewithNIVA’squalitysystemandapprovedby:

Luca NizzettoProjectManager/MainAuthor

Emmy NøklebyeQualityAssurance

Sindre LangaasResearchManager

ISBN978-82-577-7368-7NIVA-reportISSN1894-7948

©Norskinstituttforvannforskning/NorwegianInstituteforWaterResearch.Thepublicationcanbecitedfreelyifthesourceisstated.

For NIVA LucaNizzetto(PI,IMPASSECoordinator),RachelHurley,MagnusNorling,NinaBue-naventura,CecilieSingdahl-Larsen,SindreLangaas,NataliaLobo,MortenJartun

For Vrije Universiteit Am-sterdam

KeesVanGestel(PI),OscarFranken,SallaSelonen,RudoVerweij,LidiaParramonDol-cet,HibaBenguedouar,StephanvanderKint,SomayyeSadatAlavianPetroody,LyndonNiiAdjiriSackey

For Swedish University of Agriculture

MartynFutter(PI),DidierBaho,EmilijaŽilinskaitė,LuisCarlosDeSa,JohnKoestel,EliasBäckström,DennisCollentine,MircoBundschuh,EmmaLannergård,ViktoriaErikssonRusso

For IMDEA MarcoVighi(PI),EloyGarcíaCalvo(PI),AndreuRico,TheresaSchell,BelénGonzálezGaya,BeatrizPeinadoRodríguez,FranciscoMartínezSerrano

For Windsor University JillCrossman(PI),DilshadMasih,BrentNawrocki,MercedesLavoy

For Trent University JillCrossman(PI),MitchellHall

For University of Ljubljana AnitaJemecKokalj(PI),TinaSkalar,AndražDolar,ValentinaPerc.

For SYKE SallaSelonen

AcknowledgementsIMPASSEisaresearchinitiativeundertheframeoftheEUERA-NETWaterWorks2015JointCall2016Call.ERA-NETisanintegralpartofthe2016JointActivitiesdevelopedbytheWaterChallengesforaChangingWorldJointProgrammeInitiative(WaterJPI)andtheJointProgrammingInitiativeonAgriculture,FoodSecurityandClimateChange(FACCEJPI).

Thefollowinginstituteshavejointlyfinancedtheproject:TheNorwegianResearchCouncil(Norway),MINECO(Spain),SlovenianResearchAgency(Slovenia),Formas(Sweden),theNetherlandsOrganisationforScientificResearch(Netherland),CanadianResearchCouncil(Canada),SlovenianResearchAgency(Slovenia).

CreditsCopyrights:NIVA(NorwegianInstituteforWaterResearch)Publishedon1May2021

Authors of the report: Luca Nizzetto1,AndreuRico2,KeesVanGestel3,SallaSelonen4,JillCrossman5,MartynFutter6,AnitaJemecKokalj7.

1. NorwegianInstituteforWaterResearch(NIVA),Gaustadalléen21,NO-0349,Oslo,Norway.2. UniversityofAlcalaDeHenares,IMDEAWaterInstitute,Sci&TechnolCampus,AvePuntoCom2,Madrid28805,Spain.3. VrijeUniversiteitAmsterdam,FacultyofScience,DeptEcologicalSciences,DeBoelelaan1085,NL-1081HVAmsterdam,Netherlands.4. FinnishEnvironmentInstitute(SYKE),Mustialankatu3,Helsinki00790,Finland.5. UniversityofWindsor,SchoolofEnvironment,SunsetAve,Windsor,ONN9B3P4,Canada.6. SwedishUniversityofAgriculturalSciences,DeptAquaticSciences&Assessment,Uppsala,Sweden.7. UniversityofLjubljana,BiotechnologyFaculty,DeptBiology,VecnaPot111,Ljubljana1000,Slovenia

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Impacts of MicroPlastic in Agrosystems and Stream Environments

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Impacts of MicroPlastic in Agrosystems and Stream Environments