Introduction In August 2015, the Swedish Environmental Protection Agency (EPA) was commissioned by the Government to identify major sources in Sweden for the emission of microplastics into the sea and to work to reduce emissions from these sources. The Swedish EPA presents its commission in this report. We present the results of the first comprehensive survey of the sources and dispersal of microplastics in Sweden, an assessment of which of the identified sources should be primarily addressed, and the steps to be taken to prevent emissions and reduce the releases of microplastics into the sea, lakes and streams from these sources. The presence of microplastics in the marine environment has been increasingly recognized in recent years, not least at global level. Microplastic is a generic term for small plastic fragments measuring from 1 nm to 5 mm. The microplastics found in the oceans, but also in freshwater systems, have different origins. Microplastic can be unintentionally formed when plastic items deteriorate and plastic particles a reemitted, or when we do not re-use, recycle or dispose of plastic materials properly so that the plastic becomes debris that is successively degraded down into smaller and smaller pieces in nature. There is also plastic that is originally fabricated as small pellets or beads. The basis of this work has been the Swedish environmental quality objectives A Balanced Marine Environment, Flourishing Coastal Areas and Archipelagos and A Non-toxic Environment. Reduced releases of microplastics into seas, lakes and streams will contribute to achieving these objectives. The commission was conducted by the Swedish EPA in cooperation with the Agency for Marine and Water Management other relevant authorities, and with the participation of relevant organizations and other stakeholders between August 2015and May 2017. The conclusions are those of the Swedish EPA. Results Mapping of sources and dispersal pathways IVL Swedish Environmental Research Institute has, on behalf of the Swedish EPA, mapped possible sources and dispersion routes for microplastics in Sweden. Focus has been placed on onshore sources. The survey gives a first, consolidated picture of the origin of microplastics and their transport to the sea. Knowledge of how microplastics disperse from source to sea, lakes and streams remains limited. Possible pathways are via air, rainwater and snow dumping, as well as through wastewater treatment plants and slurry spreading. It has not been possible to calculate the proportion of microplastic transported to sea, lakes and streams for the majority of the mapped sources due to the lack of available data. The volumes that can be calculated are dispersion from sources where emissions occur directly to water, such as washing boat hulls, and the loss that occurs via wastewater treatment plants. The amount of microplastic that reaches Swedish coastal waters from various sources has thus not been estimated.

 7SWEDISH ENVIRONMENTAL PROTECTION AGENCY REPORT 7078MicroplasticsMajor sources of microplastics in Sweden in the light of the survey, the Swedish EPA has considered that the following sources should be addressed primarily in Sweden: Tyre and road wear, artificial grass pitches(AGPs), industrial production and handling of primary plastics, synthetic fibre laundry, boat hull paints and litter. In total, these sources account for the largest emissions of microplastics in Sweden. Assessment of the possibilities for moving towards reduced emission of microplastics in Sweden Today, there is not enough scientific knowledge to enable certain conclusions to be drawn about how microplastics from tyre and road wear, artificial grass pitches, industrial production and handling of primary plastics, textile laundry, boat hull paint and litter in Sweden are released to the seas, lakes and streams and what environmental impact they have there. We have therefore considered that the possibilities for preventing emissions and reducing the releases of microplastics are limited in the short term. At the same time, the presence of microplastics in the oceans – including in Swedish coastal waters and fresh waters – is a fact. In view of the precautionary principle, the Swedish EPA therefore calls for measures that can be implemented at reasonable costs and consequences for the stakeholders concerned, despite the uncertainties that exist. In this respect, it is important to note that there are already instruments for reducing emissions of microplastics, albeit indirectly. Many of the behave ours that cause emissions and the releases of microplastics are the same as those that cause particulate emissions in general. For example, there are instruments aimed at reducing particulate emissions to air and water. Therefore, the synergies between possible measures to reduce microplastic emissions and ongoing or planned measures in other areas, such as clean air work and non-toxic everyday life, should be exploited. Proposals for action Knowledge building is central to the prevention of emissions of microplastics in the longer term and reduction of their releases, as is dialogue and information to raise awareness of the problems of microplastics. We have therefore drawn up proposals for measures aimed primarily at raising both knowledge and awareness of microplastics through research and development, guidance, dialogue and information. In parallel with national measures, work in the EU and internationally to reduce the releases of both macro- and microplastics to seas, lakes and streams continues. 

 KNOWLEDGE BUILDING The knowledge gaps and methodological difficulties identified during the work on the commission constitute an important contribution to further work with microplastics in Sweden. We propose, among other things, that VTI (the Swedish National Road and Transport Research Institute) be commissioned by the Government to develop knowledge of microplastic emissions from road traffic. Further examples of R&D measures include evaluation of highway stormwater purification techniques, a knowledge-based review of measures to reduce losses and leakage of granulate from artificial grass pitches, screening of microplastics and measuring of plastic particles in boat hull washes. In addition, the Swedish EPA will make an inventory of the need for knowledge of microparticles, including microparticles made from plastic.

 8SWEDISH ENVIRONMENTAL PROTECTION AGENCY REPORT 7078MicroplasticsPRE-PURCHASE PROCUREMENT GROUPSA pre-purchase procurement group is a multiple year collaboration between the various procurement agencies aimed at improving the quality of procurement through joint knowledge-building and collaboration on requirements and procurement methods. We have found that pre-purchase procurement groups are an efficient way to gather and build knowledge and to create new solutions for the development of primarily artificial grass pitches, but also for the development of advanced treatment techniques for purification of wastewater treatment plants and stormwater. The Swedish EPA will initiate a pre-purchase procurement group to discuss reduced environmental impact from artificial grass pitches during 2017 and will investigate the possibilities of initiating additional pre-purchase procurement groups for, among other things, advanced wastewater treatment. GUIDELINES Guidance for supervisory agencies and companies has several objectives, such as creating the conditions for equally applied and effective supervision, clarifying rules and contributing to better self-inspection. 

The Swedish EPA will provide guidance for increased control of spill flows (untreated or incomplete treatment of water from sewerage systems or wastewater treatment plants), partly for the application of the legislation governing the use of rubber granules in artificial grass pitches, and partly for measures to minimize material losses during manufacture and processing of primary plastics. 

 INFORMATIONA number of information measures are proposed, notably in the field of textile laundry, such as providing information for consumers about the measures they can take to reduce the emission of microplastics from the use and laundry of synthetic fibres, and to reduce the amount of litter. The Swedish EPA is also planning to hold a workshop with the Swedish Chemicals Agency to consider microplastics that are caused by synthetic fibres. 

 PARTICIPATION IN THE EU AND INTERNATIONALLYA number of initiatives are under way at EU and international level to prevent and manage the presence of microplastics in the oceans. Sweden needs to continue to participate in the relevant EU and international contexts, both to benefit from the knowledge presented there and to participate in, and influence, the development of measures that have bearing on both national and global environmental and sustainability targets. Measures at EU level have been assessed as most relevant in the reduction of tyre wear and for microplastics produced by the use of textiles. Together with the Swedish Energy Agency, we propose that Sweden investigate the possibility of developing the EU’s energy label for tyres to include wear resistance and work to develop the eco design rules for washing machines. We also propose that the Swedish EPA, in connection with the revision of the reference document for textile manufacture under the EU Industrial Emissions Directive, works within the EU to produce data on the emission of microplastics from manufacturing processes in the textile industry. 

 9SWEDISH ENVIRONMENTAL PROTECTION AGENCY REPORT 7078MicroplasticsSweden should use the knowledge generated in international processes to increase its knowledge base and develop measures nationally. We can also contribute our own experience, for example, in building efficient waste management schemes, because insufficient waste management and onshore litter is the largest global source of marine refuse and microplastics in the oceans. The work of the HELCOM and OSPAR regional marine conventions is identified have been identified as important arenas for this commission. Conclusions This report has compiled existing knowledge of the origin of microplastics and transport to the sea, lakes and streams in Sweden. We demonstrate the steps that need to be taken to prevent emissions and reduce the release of microplastics from land-based sources to seas, lakes and streams. The knowledge compiled here forms a springboard from which to work. The proposed measures are a first step along the way and need to be developed and supplemented as our knowledge of microplastics increases. Microplastics are an environmental problem that transcends societal sectors to which there is no simple solution. At the same time, there are many parallels with measures that aim at reducing emissions and discharges of undesirable substances in general. The Swedish EPA therefore believes that it is of great importance to take advantage of the synergies that exist. Further investigation will need to be made of potential target conflicts that may arise. Work on this government commission has put microplastics on the agenda. A number of voluntary activities are already under way at various levels in Sweden with a view to both increasing knowledge about microplastics and how their emission isbest prevented and reduced. To reduce the presence of microplastics in seas, lakes and streams, stakeholders at all levels of society need to contribute to knowledge building and measures to reduce their emission.