Occurrence of Traffic-Derived Microplastics in Different Matrices in the Road Environment

The prevalence of microplastic contamination has raised concerns about the potential risk andimpact on the global environment. Traffic-derived microplastics, i.e., tire wear particles (TWP),polymer-modified bitumen, and road markings contribute to the emissions, and TWP areassumed to be one of the largest sources of microplastic emissions. Due to analyticaldifficulties, there is still a knowledge gap regarding transport routes, environmentalconcentrations, and toxicity. This thesis aims to investigate the occurrence of traffic-derivedmicroplastics in several traffic environments and thereby increase the understanding of theparticles

Identification of Chlorinated Fatty Acids in Standard Samples and Fish Lipids : Verification and Validation of Extraction, Transesterification and GC-MS/XSD

Chlorine gas bleaching was a common method used in pulp industries. As a consequence, significant amounts of chlorine were discharged into surrounding aquatic ecosystems, affecting the biota. Chlorinated organic pollutants are formed when chlorine react with organic material. Octadecanoic acid (stearic acid) is one of the most common saturated fatty acids in aquatic biota. In a naturally occurring process two and four chlorine atoms, respectively, are added over the unsaturated bonds, forming 9,10-dichloro octadecanoic acid and 9,10,12,13-tetrachloro octadecanoic acid. These are the chlorinated fatty acids (ClFA) under investigation in this Bachelor’s Thesis. The methodological framework for measuring ClFA is investigated in this essay. The scope is to evaluate the method of isolating and quantifying the compounds as described in Åkesson-Nilsson’s (2004) dissertation. The method includes: extraction of the lipid, transesterification (where the fatty acids, including the ClFAs, are separated from the lipids and transformed into their respective methyl esters through two methods, acidic catalysis with BF3 or H2SO4), separation (by solid phase extraction) and determination of ClFA concentration with a halogen specific detector (GC-XSD/MS). Furthermore, the scope is to investigate collected fish samples (from Norrsundet) with the abovementioned method. By making a dilution series with known concentrations it was possible to establish calibration curves, to give in an indication of the effectiveness of the method. BF3 is in need of updating due to being experienced as slower and less stable than the H2SO4-method. However, it was concluded that the H2SO4-method was more effective on the standard samples and that the BF3-method was more effective on the fish lipid samples. In one of the lipid samples (lavaret transesterified with BF3) a detectable concentration of 9,10,12,13-tetrachloro octadecanoic acid was discovered. Therefore, we question SEPAs decision to cancel investigations in Norrsundet. Our results could indicate that ClFAs are still an issue that could affect the ecosystem’s biota.

Trafiken – ett miljöproblem som rullar på

I dag står slitaget av vägar, däck och bromsar för 44 procent av Sveriges totala årliga utsläpp av inandningsbara partiklar (PM10). Slitage av däck bedöms dessutom vara den största källan till mikroplast. Är den pågående elektrifieringen lösningen, eller skapar den bara andra problem

Evaluating sweep-salting on bicycle routes in Stockholm in the winter of 2016/2017

VTI fick i uppdrag av Stockholms stad att under vintersäsongen 2016/17 fortsätta utvärdera sopsaltmetoden som används för vinterväghållning av cirka 18 mil prioriterade cykelstråk. Det är fjärde säsongen i rad som VTI genomför en uppföljning. De tidigare säsongernas resultat finns sammanställda i VTI notat 28-2015, VTI notat 29-2015 samt VTI PM 2016-12-01 (Diarienummer: 2013/0390-9.1). Sopsaltmetoden innebär att en sopvals röjer/borstar bort snön från cykelvägen som därefter prepareras med saltlösning eller befuktat salt, NaCl (natriumklorid). Saltning kan ske både i preventivt syfte, innan nederbörd för att cykelvägen ska klara lägre temperaturer och nederbörd innan tillfrysning sker, eller under ett snöfall. Det är viktigt att förhindra att snön fäster till beläggningen och blir svår att borsta bort. En av de största svårigheterna med metoden har varit att hitta borstar som är tillräckligt effektiva för att sopa bort vatten och nederbörd från cykelvägen. Om det blir vatten kvar späds saltet ut och markant högre saltgivor behöver läggas ut för att förhindra till- eller återfrysning jämfört med om vattnet sopas bort innan saltutlägg. I detta notat har vinterns mätningar sammanställts, både de kontinuerliga som genomförts på samma plats sedan projektets start och de mer specifika fokusmätningar som tagits fram till denna säsong. Vintern 2016/17 var överlag mild, med medeltemperaturer högre än det ”normala” och relativt lite nederbörd. Ett undantag är det kraftiga snöfall som startade den 8 november och lamslog hela Stockholm. Våra observationer i fält visar på att sopsaltmetoden fungerar bra så länge förarna är ute i tid, nederbörden inte blir för kraftig eller temperaturen för låg. Om en sträcka inte hinner med att åtgärdas under ett snöfall är risken stor att det bildas en isbark av kompakterad snö som är i princip omöjlig att få bort med bara borste och salt. Om en isbark uppstått är det ingen idé att sprida några gram saltlösning och borsta ytan då detta snarare polerar isen och gör den än mer hal. Det är då bättre att ploga/riva bort isbarken och därefter återgå till sopsaltning när vädret tillåterIn Stockholm, cycling as a mode of transport is promoted, especially for commuting. Public transport as well as the roadway network has reached capacity during peak hours and cycling is considered to be an advantageous alternative, since there are environmental and health benefits to gain. To encourage people to cycle during winter and at the same time reduce the number of single bicycle crashes, a high winter maintenance service level is needed. Using salt for skid control of bicycle paths could be one solution, although it has its drawbacks and difficulties. In recent years, a method using a frontmounted power broom for snow clearance and salt for de-icing (commonly called “sweep-salting”) has become popular for winter maintenance of bicycle paths in Sweden. In 2013 the city of Stockholm decided to try the “sweep-salting” method and evaluate its potential to improve the service level on bicycle routes for commuting. To optimize and develop the method, VTI has performed field studies every winter since 2013. These studies have included measurements of friction, road condition observations, measurements of residual salt on bicycle path surfaces, salt deposition at the side of bicycle paths, maintenance protocols and interviews with maintenance operators. Since all studies were done in field, in a real-life environment, the experimental work was designed according to the winter maintenance routines of the municipality and other prevailing conditions and circumstances. This report presents the results from the evaluation of the winter of 2016/2017. The evaluations show that when working successfully, the sweep-salting method creates a bare surface with higher friction than traditional ploughing and gritting. Measures must be done in time and the operating speed adjusted according to the prevailing conditions. In mild weather brine is sufficient, but with lower temperatures and heavy snowfall larger amounts of salt is needed and pre-wetted or dry salt must be used. For the method to work properly, the bicycle path construction should be of good condition without cracks or other damages in the surface. Otherwise, it is difficult to clear the surface with the broom as snow and water can be trapped in potholes and cracks, eventually creating ice patches. A sufficient drainage from the surface is also crucial as every contribution of water will dilute the salt amount on the path with a following risk of creating a slippery surface. Narrow passages and obstructing design features cause difficulties when clearing the snow, resulting in a need of larger amounts of salt to prevent icy conditions. Clearing the surface from snow and water is crucial to get a good result with the method

Evaluation of road sweepers’ ability to reduce the road dust depot in street and tunnel environments : A field study in Trondheim, Norway

VTI har i maj 2016 på uppdrag av Statens vegvesen i Trondheim genomfört en fältstudie i Strindheimtunnelen samt på Haakon VII gate med syfte att jämföra och utvärdera städmaskiners och teknikers förmåga att reducera vägdammsförrådet i gatu- och tunnelmiljöer. VTI genomförde provtagningar med dammprovtagaren Wet Dust Sampler II (WDS II) före och efter städinsatserna.  Studien visade att vägdammsförrådet blev större efter en första städinsats med BEAM rotorclean i tunneln (endast vägbana) än före städning. Detta antas bero på att vägdamm spolas ut från kanten alternativt att cementerat vägdamm i beläggningstexturen lösgjorts. Efter en andra städinsats då väggar och tak först städades varefter vägbanan städades igen kunde en sänkning av dammförrådet uppmätas, dock endast i vägbanan, inte närmast kanten. På Haakon VII gate testades två olika städmaskiner: Disa Clean och Val’Air rotor cleaner. Den förstnämnda är en torr vakuumsug medan den sistnämnda utför roterande högtryckstvättning kombinerad med vakuumsug. Körbanan delades upp i sex sektioner, där en specifik städstrategi användes i varje sektion (kallas fält i denna studie). Provtagning genomfördes i varje fält före och efter städinsats. Resultatet i denna studie visade att störst effekt erhålls vid användande av Disa Clean i kombination med högtrycksspolning samt vid användande av Val’Air rotor cleaner med en körhastighet på 3 kilometer i timmen. I båda fall uppmättes en markant skillnad i dammförråd före och efter städning.In May 2016, VTI conducted a field study in Strindheim tunnel and on Haakon VII street on behalf of the Norwegian Road Administration in Trondheim aiming at comparing and evaluating the ability of cleaning techniques to reduce the road dust depot in street and tunnel environments.  The result showed that after a first cleaning effort in the tunnel with the BEAM rotorclean (roadway only), a larger dust load was detected than before cleaning. This is believed to be due to the flushing of dust from the edge of the road or the removal of dust cemented in the road surface texture. After a second cleaning effort, where the walls and ceilings are cleaned and the road is cleaned again, a reduction in dust load could be distinguished, but only in the roadway, not near the edge. On Haakon VII street, two different cleaning machines, Disa Clean and Val’Air rotor cleaner were used, the former being a dry vacuum sweeper and the latter using rotary high pressure washing combined with vacuum. Sampling was conducted in six fields. The result showed that greatest effect was achieved with Disa Clean in combination with high pressure rinsing as well as with Val’Air rotor cleaner at a driving speed of 3 kilometer per hour. In both cases there were significant differences in dust storage before and after cleaning.Utvärdering av städmaskiner i Trondheim, 201

Wet Dust Sampler—a Sampling Method for Road Dust Quantification and Analyses

In northern countries, the climate, and consequently the use of studded tyres and winter traction sanding, causes accumulation of road dust over winter and spring, resulting in high PM10 concentrations during springtime dusting events. To quantify the dust at the road surface, a method—the wet dust sampler (WDS)— was developed allowing repeatable sampling also under wet and snowy conditions. The principle of operation is flushing high-pressurised water over a defined surface area and transferring the dust laden water into a container for further analyses. The WDS has been used for some time and is presented in detail to the international scientific community as reported by Jonsson et al. (2008) and Gustafsson et al. (2019), and in this paper, the latest version is presented together with an evaluation of its performance. To evaluate the WDS, the ejected water amount was measured, as well as water losses in different parts of the sampling system, together with indicative dust measurement using turbidity as a proxy for dust concentration. The results show that the WDS, when accounting for all losses, have a predictable and repeatable water performance, with no impact on performance based on the variety of asphalt surface types included in this study, given undamaged surfaces. The largest loss was found to be water retained on the surface, and the dust measurements imply that this might not have as large impact on the sampled dust as could be expected. A theoretical particle mass balance shows small particle losses, while field measurements show higher losses. Several tests are suggested to validate and improve on the mass balances. Finally, the WDS is found to perform well and is able to contribute to further knowledge regarding road dust implications for air pollutionQC 20200427</p

Reporting of the Government commission on microplastics from road traffic

Denna rapport är en redovisning av det regeringsuppdrag VTI fick i december 2017 om att ta fram och sprida kunskap om mikroplast från vägtrafiken och som löpte fram till den 1 juni 2021. Uppdraget omfattade en budget på totalt 20 Mkr.  Anledningen till uppdraget var bl.a. att kunskapen om mikroplast från vägtrafiken är mycket begränsad samtidigt som däck- och vägslitagepartiklar från vägtrafiken är en stor källa. Uppdraget var ett led i regeringens arbete att nationellt och internationellt genomföra insatser för att minska problemen med plast i miljön.  Rapporten är strukturerad utifrån den kunskap som specifikt efterfrågas i uppdraget, som t.ex. kunskap om hur partiklarna sprids och vad man kan göra åt det, samt vad regeringen önskar att VTI ska göra, som t.ex. skriva vetenskapliga artiklar, samverka med myndigheter och sprida kunskap. Denna rapport är en sammanfattning av de aktiviteter som genomförts och de resultat som kommit fram inom ramen för uppdraget. Kunskapen om mikroplast från däck- och vägslitagepartiklar har från en låg nivå ökat snabbt under senare år genom forskning som bedrivits inom och utanför regerings-uppdraget. Det gäller t.ex. kunskap om beredning och analys av prover, däckpartiklars fysiska och kemiska egenskaper, däck- och vägslitagepartiklars förekomst i väg- och gatumiljö, deras potentiella spridningsvägar, vilka potentiella styrmedel och åtgärder som finns.This report presents the activities and results of an assignment on microplastics from road traffic commissioned by the Swedish Government to the Swedish National Road and Transport Research Institute (VTI) in December 2017 which has run until 1 June 2021. The assignment included a budget of in total SEK 20 million.  The assignment states that VTI will ”develop and disseminate knowledge about microplastic emissions from the transport system”. The reason for the assignment was, among other things, that knowledge about microplastics from road traffic was very limited, at the same time as tire and road wear particles from road traffic had been identified as a major source of microplastics. The assignment constitutes a part of the government's work to implement nationally and internationally efforts to reduce the problems of plastics in the environment.  The report is structured based on the knowledge specifically requested in the assignment, such as knowledge about how the particles are dispersed and what can be done about it, as well as what the government wants VTI to do, such as writing scientific articles, collaborating with authorities and knowledge dissemination. This report summarizes the activities carried out and the results obtained in the framework of the assignment. Knowledge of microplastics from tire and road wear particles has increased rapidly in recent years through research conducted inside and outside of the government assignment. This applies, for example, to knowledge of the preparation and analysis of samples, the physical and chemical properties of tire particles, the presence of tire and road wear particles in the road and street environment, their potential pathways, the potential instruments and measures available

Evaluation of sweepers’ ability to reduce road dust load in street and tunnel environments in Trondheim

För att undvika överskridande av miljökvalitetsnormerna för partiklar (PM10) har Statens vegvesen Vegdirektoratet i Trondheim genomfört ett försök att rengöra en vägtunnel och en vägsträcka med tre olika städmaskiner för att minska mängden vägdamm. Ett stort antal andra tester redovisas i huvudrapporten, medan föreliggande rapport fokuserar på hur stort vägdammsförrådet varit före och efter städningen med olika maskiner i de olika miljöerna. Resultatet visar att städning minskar vägdammsförrådet effektivt i gatumiljö med två av de tre olika maskinerna, medan vägdammsförrådet ökar av städning i tunnelmiljö. En teori kan vara att detta kan bero på att även väggar och tak städas i tunnelmiljön, vilket skulle kunna medföra att städningen flyttar partiklar från tak och väggar till vägytan. Tunnelstädningen utförs med rengöringsmedel, vilket ger en annan kemisk miljö, som kan lösa upp vägdammet längre ner i texturen och tillgängliggöra det för provtagningsutrustningen.To avoid exceeding the environmental air quality standards for particulate matter (PM10) Norwegian Public Roads Administration Directorate of Public Roads (Statens vegvesen Vegdirektoratet) in Trondheim, Norway, has implemented an attempt to clean a road tunnel and a stretch of road with three different cleaning machines to reduce the amount of dust of the road. A large number of other tests is presented in the main report, while the present report focuses on how large the road dust depot has been before and after cleaning with different machines in the different environments. The results show that two of the three different machines will reduce the road dust depot efficiently in the street environment, while the road dust depot increases of cleaning in the tunnel environment. One theory might be that this may be due to the fact that even the walls and ceiling are cleaned in the tunnel environment, which could lead to the cleaning moves particles from the ceiling and walls to the road surface. Tunnel cleaning is carried out with the cleaning solution, which gives a different chemical environment, which can dissolve way the dust further down in the texture and make it for the sampler

Wet Dust Sampler—a Sampling Method for Road Dust Quantification and Analyses

In northern countries, the climate, and consequently the use of studded tyres and winter traction sanding, causes accumulation of road dust over winter and spring, resulting in high PM10 concentrations during springtime dusting events. To quantify the dust at the road surface, a method—the wet dust sampler (WDS)— was developed allowing repeatable sampling also under wet and snowy conditions. The principle of operation is flushing high-pressurised water over a defined surface area and transferring the dust laden water into a container for further analyses. The WDS has been used for some time and is presented in detail to the international scientific community as reported by Jonsson et al. (2008) and Gustafsson et al. (2019), and in this paper, the latest version is presented together with an evaluation of its performance. To evaluate the WDS, the ejected water amount was measured, as well as water losses in different parts of the sampling system, together with indicative dust measurement using turbidity as a proxy for dust concentration. The results show that the WDS, when accounting for all losses, have a predictable and repeatable water performance, with no impact on performance based on the variety of asphalt surface types included in this study, given undamaged surfaces. The largest loss was found to be water retained on the surface, and the dust measurements imply that this might not have as large impact on the sampled dust as could be expected. A theoretical particle mass balance shows small particle losses, while field measurements show higher losses. Several tests are suggested to validate and improve on the mass balances. Finally, the WDS is found to perform well and is able to contribute to further knowledge regarding road dust implications for air pollutionQC 20200427</p

Wet Dust Sampler—a Sampling Method for Road Dust Quantification and Analyses

In northern countries, the climate, and consequently the use of studded tyres and winter traction sanding, causes accumulation of road dust over winter and spring, resulting in high PM10 concentrations during springtime dusting events. To quantify the dust at the road surface, a method—the wet dust sampler (WDS)— was developed allowing repeatable sampling also under wet and snowy conditions. The principle of operation is flushing high-pressurised water over a defined surface area and transferring the dust laden water into a container for further analyses. The WDS has been used for some time and is presented in detail to the international scientific community as reported by Jonsson et al. (2008) and Gustafsson et al. (2019), and in this paper, the latest version is presented together with an evaluation of its performance. To evaluate the WDS, the ejected water amount was measured, as well as water losses in different parts of the sampling system, together with indicative dust measurement using turbidity as a proxy for dust concentration. The results show that the WDS, when accounting for all losses, have a predictable and repeatable water performance, with no impact on performance based on the variety of asphalt surface types included in this study, given undamaged surfaces. The largest loss was found to be water retained on the surface, and the dust measurements imply that this might not have as large impact on the sampled dust as could be expected. A theoretical particle mass balance shows small particle losses, while field measurements show higher losses. Several tests are suggested to validate and improve on the mass balances. Finally, the WDS is found to perform well and is able to contribute to further knowledge regarding road dust implications for air pollutionQC 20200427</p