Article

Measurement of airborne concentrations of tire and road wear particles in urban and rural areas of France, Japan, and the United States

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Abstract

In addition to industrial facilities, fuel combustion, forest fires and dust erosion, exhaust and non-exhaust vehicle emissions are an important source of ambient air respirable particulate matter (PM10). Non-exhaust vehicle emissions are formed from wear particles of vehicle components such as brakes, clutches, chassis and tires. Although the non-exhaust particles are relatively minor contributors to the overall ambient air particulate load, reliable exposure estimates are few. In this study, a global sampling program was conducted to quantify tire and road wear particles (TRWP) in the ambient air in order to understand potential human exposures and the overall contribution of these particles to the PM10. The sampling was conducted in Europe, the United States and Japan and the sampling locations were selected to represent a variety of settings including both rural and urban core; and within each residential, commercial and recreational receptors. The air samples were analyzed using validated chemical markers for rubber polymer based on a pyrolysis technique. Results indicated that TRWP concentrations in the PM10 fraction were low with averages ranging from 0.05 to 0.70 μg m−3, representing an average PM10 contribution of 0.84%. The TRWP concentration in air was associated with traffic load and population density, but the trend was not statistically significant. Further, significant differences across days were not observed. This study provides a robust dataset to understand potential human exposures to airborne TRWP.

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... Différentes roches à l'origine des granulats naturels constitutifs des revêtements43 Tableau 3 : L'estimation de la contribution (%) des pneus à la matière particulaire atmosphérique présente en bord de route, tableau inspiré de (Panko et al., 2013;Amato, 2018) ...
... sur les émissions. Néanmoins, elles ne considèrent pas la contribution de la remise en suspension de la poussière générée par l'ensemble du véhicule ou par les véhicules voisins, ni la contamination par la poussière de l'environnement proche dépendant entre autre des conditions météorologiques (Fauser, 1999) Suède 0,1 -3,9% -- (Sjödin et al., 2010) Corée 3 -4% 4 -7% France 0,62% -- (Panko et al., 2013) Tableau 3 : L'estimation de la contribution (%) des pneus à la matière particulaire atmosphérique présente en bord de route, tableau inspiré de (Panko et al., 2013;Amato, 2018). ...
... sur les émissions. Néanmoins, elles ne considèrent pas la contribution de la remise en suspension de la poussière générée par l'ensemble du véhicule ou par les véhicules voisins, ni la contamination par la poussière de l'environnement proche dépendant entre autre des conditions météorologiques (Fauser, 1999) Suède 0,1 -3,9% -- (Sjödin et al., 2010) Corée 3 -4% 4 -7% France 0,62% -- (Panko et al., 2013) Tableau 3 : L'estimation de la contribution (%) des pneus à la matière particulaire atmosphérique présente en bord de route, tableau inspiré de (Panko et al., 2013;Amato, 2018). ...
Thesis
Les particules émises hors échappement (PHE), provenant de l’usure des freins et du contact pneu-chaussée, contribuent significativement à la dégradation de la qualité de l’air et présentent un risque majeur pour la santé humaine. Ces émissions proviennent de sources multiples et sont actuellement mal décrites. De plus, les méthodes utilisées pour les appréhender sont souvent inadaptées. Pour tenter d’affiner cette problématique, ce travail de thèse s’est attaché à caractériser la physico-chimie des PHE ainsi que leurs dynamiques d’émission. Des expérimentations complémentaires ont été menées au moyen de grands équipements scientifiques et dans différents environnements. Celles réalisées au laboratoire, sur un banc à rouleau, se sont focalisées sur les particules d’usure des freins. Des mesures embarquées, effectuées avec un véhicule instrumenté sur une piste d’essais et sur route, ont permis d’étudier les particules émises par le contact pneu-chaussée. Finalement, des campagnes de mesures ont été effectuées en bord de route afin d’évaluer la contribution des PHE dans l’atmosphère proche des axes routiers.Un des principaux résultats met en lumière que les PHE appartiennent non seulement au mode grossier, prépondérant en masse, mais également aux modes fin et ultrafin prépondérants en nombre. Les émissions des nanoparticules émises par l’usure des freins dépendent de la température de l’interface plaquettes-disque et par conséquent de la force et de la fréquence de freinage. Les émissions des particules du contact pneu-chaussée augmentent avec la vitesse et les variations brutales de celle-ci. À l’image des sources, la composition chimique des PHE est très diverse. Elle est fortement liée à la composition des plaquettes et du disque des freins, des pneus, de la chaussée et de l’ensemble de contaminants déposés sur la route et remis en suspension. Ces PHE sont néanmoins souvent formées par des composés carbonés, avec une teneur importante en métaux et autres minéraux (ex. Fe, Cu, Al, Si, S, Ca…etc.). En fait, il existerait un lien entre émissions de PHE des freins et du contact pneu-chaussée : les premières modifient la dynamique d’émission de secondes via la constitution d’un troisième corps abrasif déposé sur la chaussée. Ceci a été exploré et discuté en relation avec l’influence de la remise en suspension ; étant une source majeure de PHE. Un intérêt de ce travail est, entre autre, d’estimer l'exposition aux PHE fines et ultrafines à proximité des grands axes routiers. Il permet aussi d’évaluer l’influence des principaux paramètres contrôlant les émissions des PHE et, au-delà, d’émettre des recommandations visant à réduire ces émissions et à améliorer la mobilité durable
... Typically, the larger size fractions of TRWPs will be deposited on the road surface, whereas the smaller particles become airborne, thus contributing to the PM load in the atmosphere. Under typical driving conditions, cars are estimated to emit <10% by mass of their total tire wear as PM 10 [55,80,94,104,105]. Roadside ambient air contains TRWPs in concentrations of up to 11 μg/m 3 , based on highest measured concentrations of tire markers [80]. ...
... The size of individual TRWPs occurring in ambient air varies from ultrafine to super-coarse, but the TRWP mass concentrations in the smallest fractions are generally low [15,21,49,63,70,105,106]. ...
... TRWPs have been estimated to contribute 5-10% of the total global MPs ending up in the oceans [1]. Moreover, it has been estimated that the contribution by weight of TRWPs in the ambient air is <7% of PM 2.5 and < 11% of PM 10 [1,11,17,63,70,105], which suggests that, even though TRWPs emitted into the atmosphere are coarser than PM from exhaust emissions, they may still represent a human health risk as a result of inhalation [124]. The potential toxicity of TRWPs at environmentally relevant concentrations, therefore, must be carefully assessed, especially because they contain relatively high concentrations of some components of concern, including Zn, butadiene, benzothiazoles, and PAHs, which may be released from or leached out of the TRWPs during their physical, chemical (including photo-oxidation), and microbial degradation in the environment (i.e., weathering) or within the bodies of organisms [6,10,17,80,89,119,[125][126][127]. ...
... Europe shows tyre and brake wear emissions (combined) and road abrasion emissions separately, but excludes resuspension; the U.S. includes resuspension (paved road dust), but combines tyre and brake wear with exhaust emissions. A report by Panko et al. (2013) states that according to the USEPA, tyre wear contributed 15% of total vehicle emissions of PM 10 in 2008 which compares with a value of 17% in the UK for the same year (NAEI, 2020). On-line inventory data are available for the State of California where emissions for all sources can be seen with tyre and brake wear and resuspension (paved road dust) viewed separately. ...
... Electron microscopy can reveal the composition and morphology of tyre dust particles. Studies by Kreider et al. (2010) and Panko et al. (2013) have shown from on-road studies the association of tyre rubber internally mixed with other constituents such as road surface wear, road dust or other traffic-related sources within individual particles, known as Tyre Road Wear Particles (TRWP). Aerosol Time-of-Flight Mass Spectrometry (ATOFMS) is an alternative form of single particle analysis and has also shown an association of crustal elements with particles derived from tyre dust (Dall'Osto et al., 2014). ...
... A proportion of tyre wear will not be released to air but remain on the road surface or enter the environment in run-off. A further consideration in terming tyre wear as plastic arises from the way in which tyre wear particles may be substantially (50%) internally mixed with road-wear fragments (Kreider et al., 2010;Panko et al., 2013Panko et al., , 2019. ...
Article
As exhaust emissions of particles and volatile organic compounds (VOC) from road vehicles have 40 progressively come under greater control, non-exhaust emissions have become an increasing 41 proportion of the total emissions, and in many countries now exceed exhaust emissions. Non-42 exhaust particle emissions arise from abrasion of the brakes and tyres and wear of the road surface, 43 as well as from resuspension of road dusts. The national emissions, particle size distributions and 44 chemical composition of each of these sources is reviewed. Most estimates of airborne 45 concentrations derive from the use of chemical tracers of specific emissions; the tracers and 46 airborne concentrations estimated from their use are considered. Particle size distributions have 47 been measured both in the laboratory and in field studies, and generally show particles to be in both 48 the coarse (PM2.5-10) and fine (PM2.5) fractions, with a larger proportion in the former. The 49 introduction of battery electric vehicles is concluded to have only a small effect on overall road 50 traffic particle emissions. Approaches to numerical modelling of non-exhaust particles in the 51 atmosphere are reviewed. Abatement measures include engineering controls, especially for brake 52 wear, improved materials (e.g. for tyre wear) and road surface cleaning and dust suppressants for 53 resuspension. Emissions from solvents in screen wash and de-icers now dominate VOC emissions 54 from traffic in the UK, and exhibit a very different composition to exhaust VOC emissions. Likely 55 future trends in non-exhaust particle emissions are described.
... For PYR-GC/MS there is also the possibility of applying different types of pyrolyzers, such as the resistive PYR-GC/MS (Miller et al., 2022), Curie point PYR-GC/MS (Miller et al., 2022;Panko et al., 2013;Panko et al., 2019;Unice et al., 2012a;Unice et al., 2013) and the microfurnace PYR-GC/MS (Goßmann et al., 2021;Rauert et al., 2021;Rødland et al., 2022a;Rødland et al., 2022b;Youn et al., 2021). These have different characteristics in terms of how samples are thermally decomposed and how much material can be analyzed for each sample. ...
... However, the observed acute toxicity found for coho salmon might be species-specific, as recent studies have found no acute toxicity for other organisms or even other salmon species tested (chum salmon, Oncorhynchus keta) (Hiki et al., 2021;McIntyre et al., 2021). As the concentrations of tire particles found for roadside snow (76-19,000 mg/L) is within the range where toxic effects on some organisms have been confirmed by previous studies (Gualtieri et al., 2005;Khan et al., 2019;McIntyre et al., 2021;Panko et al., 2013;Tian et al., 2021), it is possible that toxic effects could be observed if meltwater is released directly into a recipient, and especially smaller recipients with lower dilution capacity. Müller et al. (2022) showed that less than 20% of the organic chemical in tires had leached completely by 28 days in water, suggesting that tire particles left in an aquatic environment will continue to leach out chemicals over time unless they are removed. ...
... Tire tread wear is one of principal non-exhaust dust sources produced from road traffic along with brake and pavement wear [1][2][3][4][5][6][7][8][9][10]. Abraded tire tread material without other particles is called tire tread wear particles or tire wear particles (TWP), and TWP combined with other particles including road wear materials deposited on the road is called tire-road wear particle (TRWP) [2,4,8,9,11]. ...
... Tire tread wear is one of principal non-exhaust dust sources produced from road traffic along with brake and pavement wear [1][2][3][4][5][6][7][8][9][10]. Abraded tire tread material without other particles is called tire tread wear particles or tire wear particles (TWP), and TWP combined with other particles including road wear materials deposited on the road is called tire-road wear particle (TRWP) [2,4,8,9,11]. Tire tread contacts with the road surface including lots of mineral particles (MPs) during driving and it is abraded by friction with the road surface. During the wear process, the tire tread interacts with many MPs and some MPs will be stuck into the rubber to produce TRWPs. ...
Article
Full-text available
Tire tread wear particles (TWPs) are one of major sources of microplastics in the environment. Tire–road wear particles (TRWPs) are mainly composed of TWPs and mineral particles (MPs), and many have long shapes. In the present work, a preparation method of model TRWPs similar to those found in the environment was developed. The model TRWPs were made of TWPs of 212–500 μm and MPs of 20–38 μm. Model TWPs were prepared using a model tire tread compound and indoor abrasion tester while model MPs were prepared by crushing granite rock. The TWPs and MPs were mixed and compressed using a stainless steel roller. The TWPs were treated with chloroform to make them stickier. Many MPs in the model TRWP were deeply stuck into the TWPs. The proper weight ratio of MP and TWP was MP:TWP = 10:1, and the double step pressing procedure was good for the preparation of model TRWPs. The model TRWPs were characterized using scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The model TRWPs had long shapes and the MP content was about 10%. The model TRWPs made of TWPs and asphalt pavement wear particles showed plate-type particles deeply stuck into the TWP. Characteristics of model TRWPs can be controlled by employing various kinds and sizes of TWPs and MPs. The well-defined model TRWPs can be used as the reference TRWPs for tracing the pollutants.
... Few studies have attested traffic MPs to be part of principal sources of environmental MPs (Baensch-Baltruschat et al., 2020). Panko et al. (2013) reported up to 0.84% of PM 10 to be tyre wear and tear particles when Grigoratos and Martini (2014) and Kole et al. (2017) concluded that 0.1-10% of PM 10 and 3-7% of atmospheric PM 2.5 are composed of tyre wear and tear particles. Ketzel et al. (2007) revealed that 50-85% of traffic-emitted PM 10 exhibit a non-exhaust origin. ...
... Ketzel et al. (2007) revealed that 50-85% of traffic-emitted PM 10 exhibit a non-exhaust origin. Studies by Panko et al. (2013) and Kooi et al. (2018) ascribed the fractions of 28% and 30% respectively for MPs pollution in global oceans and rivers, to be tyre wear and tear. Kole et al. (2017) reported a proportion of 5-10% for ocean MPs as being tyre wear and tear. ...
Article
Full-text available
Micro-sized plastics were first examined for atmospheric environment in 2016. From then on, they have been detected in both indoor and outdoor atmospheric samples, with indoor environments demonstrated as containing a big proportion of these particles. The sparse distribution of these particles, is attributed to their swift and long distance transportation that is mainly eased by their tiny size (1 μm to 5 mm) and low density. Due to ongoing limitation on detectable size, analysis methods together with a lack of standardized sampling and analytical procedures, few studies were conducted on airborne microplastics (MPs). Thus, the facts regarding the occurrence, global spatial distribution, fate, and threats to ecosystem and human health of airborne MPs, are still far from being fully clarified. This literature review is a broad depiction of a state of knowledge on atmospheric MPs. Within it, robust and concise information on the sources, inspection, transport, and threats pertaining to airborne MPs are presented. Particularly, the paper entails some information concerning traffic-generated MPs pollution, which has not been frequently discussed within previously published reports. In addition, this paper has widely unveiled sectors and aspects in need of further attention, with the gaps to be filled pinpointed.
... As it has been mentioned in the previous section, road surfaces are commonly made of asphalt which is a mix of aggregates (95% composition) and asphalt binder (5% composition, Pérez-Fortes 2020). Thus, these dust particles are formed by hydrocarbons from asphalt binder and mineral rests from aggregates (Kreider et al. 2010;Panko et al. 2013;Unice et al. 2013;Kovochich et al. 2021). These particles can be suspended on air, trapped and accumulated on road surfaces, or washed-off by rainfalls or storms (Gustafsson et al. 2008;Panko et al. 2013;Unice et al. 2013;Unice et al. 2019;Kovochich et al. 2021). ...
... Thus, these dust particles are formed by hydrocarbons from asphalt binder and mineral rests from aggregates (Kreider et al. 2010;Panko et al. 2013;Unice et al. 2013;Kovochich et al. 2021). These particles can be suspended on air, trapped and accumulated on road surfaces, or washed-off by rainfalls or storms (Gustafsson et al. 2008;Panko et al. 2013;Unice et al. 2013;Unice et al. 2019;Kovochich et al. 2021). From mineral rests, it must be highlighted that the use of waste products as aggregates such as blast furnace slags, steel slags, fly ashes, or bottom ashes can produce the accumulation of heavy Fig. 1 Influence of road macro and micro-texture on pavement/ tire surface interaction (based on Wambold et al. 1995 categories andCackler et al. 2006 processes) metals such as Cd, Ni, Pb, or As due to long-term leaching processes (Folkeson et al. 2009;Hu et al. 2020). ...
Article
Full-text available
Road pavements are exposed to traffic loading and external deterioration agents which both can compromise tire-pavement interactions, posing a threat to road safety. The surface wear generates crushed pavement materials or tire rubber wear particles which, combined with other contaminants, negatively impact the environment. In fact, these particles may remain on the road surface; adhere to tires; become airborne; or drain by rainfall to roadsides, waterways, lakes, and even open oceans. Therefore, the presence of road contaminants on road infrastructure pavements is a concern for both road safety and the environment. Although the condition of pavement, traffic intensity, airborne dust emissions, and roadside environments are significantly monitored by road practitioners, especially in urban areas, there is still a need to better evaluate the pollutants remaining on road surfaces. It is known that particles smaller than 40 μm can be trapped within micro-asperities and remain on road surfaces, while particles of larger sizes can be transported by rainfall. However, it is difficult to mobilize particles with sizes larger than 105 μm by storm water runoffs, which tend to remain on road surfaces. Hence, not only rainfall characteristics are responsible of particle’s kinetics, but also particle’s size and road surface roughness are important. Therefore, this paper presents an overview of road safety and environmental concerns around contaminants, highlighting the importance of the road surface characteristics in their behavior. Finally, the current methods to measure road surface characteristics and their application for environmental and safety issues are discussed.
... In general, TWPs exist as tire-road wear particles (TRWPs) in the form of TWP encrusted with various mineral particles [2]. Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) has been widely used for the analysis of TRWPs [2,[21][22][23]. The contribution levels of TRWPs to PM 10 collected in France, USA, and Japan were assessed using Py-GC/MS, and it was reported that there were TRWPs of 0.14-2.80% in the PM 10 samples [22]. ...
... Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) has been widely used for the analysis of TRWPs [2,[21][22][23]. The contribution levels of TRWPs to PM 10 collected in France, USA, and Japan were assessed using Py-GC/MS, and it was reported that there were TRWPs of 0.14-2.80% in the PM 10 samples [22]. PM 2.5 samples collected near houses, parks, schools, and businesses in Europe (London), Japan (Tokyo), and US (Los Angeles) were also analyzed using Py-GC/MS, and it was reported that TRWP contents in the PM 2.5 samples were 0.11-0.49%, ...
Article
Full-text available
Particulate matters (PMs) such as PM10 and PM2.5 were collected at a bus stop and were analyzed using pyrolysis-gas chromatography/mass spectrometry to identify organic polymeric materials in them. The major pyrolysis products of the PM samples were isoprene, toluene, styrene, dipentene, and 1-alkenes. The pyrolysis products generated from the PM samples were identified using reference polymeric samples such as common rubbers (natural rubber, butadiene rubber, and styrene-butadiene rubber), common plastics (polyethylene, polypropylene, polystyrene, and poly(ethylene terephthalate)), plant-related components (bark, wood, and leaf), and bitumen. The major sources of the principal polymeric materials in the PM samples were found to be the abrasion of the tire tread and asphalt pavement, plant-related components, and lint from polyester fabric. The particles produced by the abrasion of the tire tread and asphalt pavement on the road were non-exhaustive sources, while the plant-related components and lint from polyester fabric were inflowed from the outside.
... Kole et al. (2015) comprehensively estimated the amount of TWP ending up in environmental compartments in the Netherlands, and suggested that 67% of TWP end up in soils, 12% in air, 6% in surface waters and 15% in sewers (Kole et al., 2015). In addition, Panko et al. (2013a) also pointed out that nearly two thirds of TWP end up in soils (Panko et al., 2013a). Thus, soils are likely the largest reservoir of TWP in the environment, and TWP have been detected in soils adjacent to roads, green belt soil and even in agricultural soil Zhang et al., 2018), indicating a likely ubiquitous pollution of TWP in soil ecosystems. ...
... Kole et al. (2015) comprehensively estimated the amount of TWP ending up in environmental compartments in the Netherlands, and suggested that 67% of TWP end up in soils, 12% in air, 6% in surface waters and 15% in sewers (Kole et al., 2015). In addition, Panko et al. (2013a) also pointed out that nearly two thirds of TWP end up in soils (Panko et al., 2013a). Thus, soils are likely the largest reservoir of TWP in the environment, and TWP have been detected in soils adjacent to roads, green belt soil and even in agricultural soil Zhang et al., 2018), indicating a likely ubiquitous pollution of TWP in soil ecosystems. ...
Article
Tire wear particles (TWP) have caused widespread contamination in the environment. However, their behavior and potential impacts in soil remain unclear since studies have so far been mainly conducted in aquatic ecosystems. It is possible that soil ecosystems are already under pressure from pollution by TWP. We here firstly synthesize knowledge about the composition, distribution, and behavior of TWP in soils. By comparing with effects of microplastics (MP) in soil, we further outline several potential impacts of TWP on soil biota and the underpinning mechanisms, and highlight the multiple pathways leading to adverse impacts of TWP on soil microbiota, soil fauna and plants. Furthermore, current knowledge about the effects of TWP is mostly based on single soil microbial species, which may underestimate the effects because of cascading consequences at the community and ecosystem levels. Therefore, more research is urgently needed to clarify the behavior and impacts of TWP from the individual organism to the Earth system level. We suggest that TWP may lead to changes in essential ecosystem services and multifunctionality, and therefore represent an emerging threat to soil health.
... Kupiainen et al. [28] reported that PM10 EF of friction tire was 9.0 mg/ (km·vehicle), Sjódin et al. [30] reported that PM10 EF of summer tire was 3.8 mg/(km·vehicle), and PM10 emission rate in road research conducted by Panko et al. [68] was 7.0 mg/km, which was close to PM10 EF (5.0 mg/ (km·vehicle)) of light vehicles reported by EPA in the early stage, and 6.0-9.0 mg/(km·vehicle) in the research by Rogge et al. [69] . On the other hand, the study of Sjödin et al. [30] shows that the PM10 EF of stud tire is 350 mg/(km·vehicle), and its EFs is significantly higher than that of other types of tires; the conclusion of this study is that the PM10 EFs of light vehicle friction tire measured directly is in the range of 3.8-9.0 ...
... Sjödin et al. [30] , 2010 Road simulation experiment 3.8 CEPMEIP [73] , 2012 Emission inventory 4.5 NAEI [64] , 2012 Emission inventory 7.0 Panko et al. [68] , 2013 ...
Article
Full-text available
According to the source, particulate matter produced during vehicle driving can be divided into exhaust emission and non-exhaust emission. Exhaust emission includes exhaust pipe emission and crankcase emission, while non-exhaust emission includes brake wear, tire wear, road wear and road dust. For a long time, it has been considered that the particulate matter pollution of motor vehicles mainly comes from exhaust emissions, and the control of particulate matter pollution in various countries is mainly concentrated in the tail gas. However, with the continuous tightening of emission standards, the emission of particulate matter has been reduced, but also makes the environmental pollution of non-exhaust particulate matter increasingly prominent. This paper summarizes the research on vehicle non-exhaust particulate matter emissions, aiming to emphasize the importance of non-exhaust particulate matter emissions and the necessity of legislation, so as to reduce their contribution to environmental particulate matter concentration.
... By using styrene butadiene as the marker, TWPs were found to account for 3.4%-8.2% of the total particulate matters in street runoff samples (Eisentraut et al., 2018). Pyrolysis-gas chromatography coupled with mass spectrometry (Py-GC-MS) can also identify TMPs using polymer-specific decomposition products as markers but sample pretreatments are necessary (Fischer and Scholz-Bottcher, 2017;ISO, 2017;Panko et al., 2013a). Herein, Panko et al. (2013a) demonstrated that TWPs concentrations in the PM 10 fraction (~0.84%) were low averaging 0.05 to 0.70 μg/m 3 . ...
... Pyrolysis-gas chromatography coupled with mass spectrometry (Py-GC-MS) can also identify TMPs using polymer-specific decomposition products as markers but sample pretreatments are necessary (Fischer and Scholz-Bottcher, 2017;ISO, 2017;Panko et al., 2013a). Herein, Panko et al. (2013a) demonstrated that TWPs concentrations in the PM 10 fraction (~0.84%) were low averaging 0.05 to 0.70 μg/m 3 . Gossmann et al. (2021) identified and quantified TWP in complex environmental samples such as road dust, fresh water and marine sediments, blue mussels, and marine salts using Py-GC/MS. ...
Article
Tire microplastics (TMPs) are identified as one of the most abundant types of microplastics, which originate from rubber with intended or unintended release. While increasing knowledge about TMPs concentrates on tire wear particles (TWPs), TMPs from other potential sources like recycled tire crumb (RTC) and tire repair-polished debris (TRD) are much less understood. Excessive levels of TMPs and their additives have been fragmentarily reported in the environment. The accumulating environmental TMPs from different sources may directly or indirectly cause adverse impacts on the environment and human health. The objectives of this review are to (1) summarize the properties, abundance, and sources of TMPs in the environment; (2) analyze the environmental fates and behaviors of TMPs, including their roles in carrying abiotic and biotic co-contaminants; (3) evaluate the potential impacts of TMPs on terrestrial and aquatic organisms, as well as human; and (4) discuss the potential solutions to mitigate the TMP pollution. By collecting and analyzing the up-to-date literature, this review enhances our better understanding of the environmental occurrence, fates, impacts, and potential solutions of TMPs, and further highlights critical knowledge gaps and future research directions that require cooperative efforts of scientists, policymakers, and public educators.
... A literature review (Wagner et al., 2018) shows that the share of TWPs of non-exhaust emissions from traffic is 5-30%. Other studies on aerosols or deposited dust show that the size of TWPs was found to be between 10 nm and several 100 μm (from PM 0.1 to PM > 10 ) (Aatmeeyata et al., 2009;Dahl et al., 2006;Kreider et al., 2010;Panko et al., 2013): ...
... In summary, all non-exhaust traffic-related emissions (TSP total, nonexhaust ) contribute 9.3% to the national TSP emissions across Austria, which were about 38,000 t/y in 2018 (Umweltbundesamt, 2021). Literature data show that total traffic-related PM emissions can contribute between 5 and 80% to total airborne emissions, which is mainly influenced by traffic load, populations density and location (Panko et al., 2013;Pant and Harrison, 2013). For the year 2018, the Environment Agency Austria reported that road transportation contributes to 13% (4,980 t/y) of the overall TSP, which is the sum of exhaust and non-exhaust emissions in Austria (Umweltbundesamt, 2021). ...
Article
Full-text available
The emissions of tyre wear particles (TWPs) into the environment are increasing and have negative impacts on the environment and human health. The aim of this study was therefore to establish a mass balance for vehicle tyres und TWP emissions in Austria using static material flow analysis, which enabled a quantification of mass flows of rubber including carbon black as the most mass-relevant tyre filler. Vehicle-specific and mileage-dependent emission factors were used to calculate the TWP emissions. The results for the year 2018 indicate that 80% of the tyre rubber remained in use, while 14% was re-treaded, recycled, incinerated or exported as end-of-life tyres and 6% was emitted as TWPs to air, soil or surface water. Of these 21,200 t/y released and dissipative lost TWPs, 6% were microscale, with a possible size between 0.1 and 10 μm, and 0.3% were nanoscale below 0.1 μm. The mass balance on the substance level shows that the TWPs contained 5500 t/y of carbon black emitted in the form of airborne TWPs (6%) or entering in the soil or surface waters (47% each). Regarding air pollution from road vehicles, about 3600 t/y were non-exhaust emissions, including tyre, brake and road-surface wear, which contributed to 9% of total dust emissions across Austria. Scenario analysis for 2050 with regard to e-mobility and the European Green Deal reveals that non-exhaust emissions can only be significantly reduced by a general reduction of the mileage or an environmentally friendly tyre design. This modelling approach provides a solid basis for decision makers in traffic planning as well as for chemical risk assessment. However, dynamic models with higher temporal and spatial resolution are needed to predict future mass flows of TWPs and their environmental fate, including their degradation products and possible accumulation effects.
... Kole et al. (2017) estimate the global annual emission of particles from tires to be more than 3.3 megatons. Although partially retained by separate sewer systems in urban areas, approximately two thirds of these particles end up in soils via runoff or transport by air (Panko et al., 2013). Amounts of TPs in the soil vary a lot: depending on the distance from the road, transport dynamics and the traffic frequency, concentrations can range from 0.1-117 g kg -1 (Wik and Dave, 2009;Wagner et al., 2018;Baensch-Baltruschat et al., 2020). ...
Article
Full-text available
Tire particles (TPs) are a major source of microplastic on land, and considering their chemical composition, they represent a potential hazard for the terrestrial environment. We studied the effects of TPs at environmentally relevant concentrations along a wide concentration gradient (0–160 mg g ⁻¹ ) and tested the effects on plant growth, soil pH and the key ecosystem process of litter decomposition and soil respiration. The addition of TPs negatively affected shoot and root growth already at low concentrations. Tea litter decomposition slightly increased with lower additions of TPs but decreased later on. Soil pH increased until a TP concentration of 80 mg g ⁻¹ and leveled off afterwards. Soil respiration clearly increased with increasing concentration of added TPs. Plant growth was likely reduced with starting contamination and stopped when contamination reached a certain level in the soil. The presence of TPs altered a number of biogeochemical soil parameters that can have further effects on plant performance. Considering the quantities of yearly produced TPs, their persistence, and toxic potential, we assume that these particles will eventually have a significant impact on terrestrial ecosystems.
... The street dust samples were obtained from 15 different sites where MPs accounted for 78% of the total particles measured while MRs accounted for 22%. Other studies have demonstrated that average airborne TRWP concentration typically ranged from 0.05 to 0.70 μg/m 3 (Panko et al., 2013;Unice et al., 2019). TRWP concentration in air has been associated with traffic load and population density; more research is needed to distinguish between TRWP and other sources of MPs in air in high-traffic areas. ...
... TWP can also contribute to airborne emissions (PM 10 or PM 2.5 ) especially close to streets (e. g. Baensch-Baltruschat et al., 2020;Panko et al., 2013). ...
Article
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Tire wear particle (TWP) emissions are gaining more attention since they are considered to contribute a major share to the overall microplastic emissions and are suspected to be harmful to flora, fauna and humans. Hence, recent studies derived country-based TWP emissions to better understand the significance of the problem using either tire emission factors (EF) or a material flow analysis (MFA) of tires. However, all 14 country-based TWP emission studies found and published since the year 2000 base their calculation on other studies rather than own measurements. Therefore, we started to search for the actual TWP measurements which the 14 studies would rely on. As a result, we found a network of 63 studies which were used to derive TWP emissions in different countries and regions. Only in few cases (12%) TWP emission studies reference directly to a measurement study to derive TWP emissions, but mostly (63%) they rely on reviews or summarizing studies. Additionally, we could not obtain 25 studies in the analysed network. In total we found nine studies which actually measured TWP emissions. Out of these four studies originate from the 1970s, one analysed only light vehicles and one only considered buses. Thus, only three non peer-reviewed studies were considered to show trustful results which were cited a maximum of three times in the network. The obtained 14 country-based studies suggest TWP emissions of about 1.3 kg capita-1 year-1 for the EF approach and 2.0 kg capita-1 year-1 for the MFA approach (overall range: 0.9-2.5 kg capita-1 year-1). Consequently, we call for an urgent need to minimize uncertainties of TWP emission estimates to better understand the contribution of TWP to the overall microplastic pollution of the environment. A better understanding about quantities could also help to better address the risk of environmental pollution by TWP.
... Roads, motor vehicle traffic, tire wear, rain events, and untreated stormwater discharges are global phenomena. Although estimates of TWP and TWP-derived chemical concentrations in aquatic environments remain uncertain, 27,43,44 it is clear that large numbers of TWP are transported into surface waters, 45 and chemicals leaching from these particles are ubiquitous in receiving waters and sediments. 24,27,46,47 Importantly, the current study suggests that it is primarily the chemicals leaching from TWP rather than the TWP themselves that pose a threat in receiving waters. ...
Article
Full-text available
Tire tread wear particles (TWP) are increasingly recognized as a global pollutant of surface waters, but their impact on biota in receiving waters is rarely addressed. In the developed U.S. Pacific Northwest, acute mortality of adult coho salmon (Oncorhynchus kisutch) follows rain events and is correlated with roadway density. Roadway runoff experimentally triggers behavioral symptoms and associated changes in blood indicative of cardiorespiratory distress prior to death. Closely related chum salmon (O. keta) lack an equivalent response. Acute mortality of juvenile coho was recently experimentally linked to a transformation product of a tire-derived chemical. We evaluated whether TWP leachate is sufficient to trigger the acute mortality syndrome in adult coho salmon. We characterized the acute response of adult coho and chum salmon to TWP leachate (survival, behavior, blood physiology) and compared it with that caused by roadway runoff. TWP leachate was acutely lethal to coho at concentrations similar to roadway runoff, with the same behaviors and blood parameters impacted. As with runoff, chum salmon appeared insensitive to TWP leachate at concentrations lethal to coho. Our results confirm that environmentally relevant TWP exposures cause acute mortalities of a keystone aquatic species.
... Thermogravimetric methods, including pyrolysis-gas chromatography-mass spectrometry (py-GC-MS) and thermal extraction desorption-gas chromatography-mass spectrometry (TED-GC-MS) represent an emerging analytical technology for environmental TRWP mass characterization. These methods rely on polymeric decomposition products as characteristic markers (Unice, Kreider, and Panko 2012;Youn et al. 2021;Eisentraut et al. 2018;Panko et al. 2013;Unice, Kreider, and Panko 2013;Baensch-Baltruschat et al. 2020;Wagner et al. 2018). Notably, tire tread contains abundant elastomer quantities that produce dimeric pyrolysis products well-suited for py-GC-MS analysis, including isoprene rubbers (e.g., natural rubber (NR) or synthetic isoprene rubber (IR), butadiene rubber (BR), and styrene-butadiene rubber (SBR)) (Unice, Kreider, and Panko 2012). ...
Article
Full-text available
Thermogravimetric methods with internal polymer standards have successfully quantified environmental tire and road wear particle (TRWP) concentrations. However, TRWP quantification in environmental matrices via pyrolysis-gas chromatography-mass spectrometry (py-GC-MS) using butadiene rubber (BR) and styrene-butadiene rubber (SBR) marker 4-vinylcyclohexene (4-VCH; 1,4-butadiene-1,4-buta-diene dimer) may be uncertain because of variable polymer compositions and BR and SBR microstructures. To determine if tire polymer microstructure is contributing to potentially over-or underestimating TRWP in the environment in py-GC-MS analyses, SBR materials (n ¼ 8) commonly found in tire tread with varying micro-structure were quantified via py-GC-MS, using 4-VCH and the deuter-ated internal standard d-4-VCH to provide a response ratio for each polymer. The response ratios of the dimer response to the total polymer quantity (instrument response slope) varied up to 6.8-fold for SBR, with a reduction to a 3.6-fold range when the polymer quantity was expressed as 1,4-butadiene mass rather than total polymer mass. Variability was reduced further when considering the polymer-ization method for emulsion-SBRs (n ¼ 3; 1.4-fold range), but not solution-SBRs (n ¼ 5; 2.7-fold range), which reflects the random versus structured heterosequencing of the two rubber types, respectively. Our findings suggest that py-GC-MS response should be interpreted based on empirical analysis of an appropriate number of regionally representative tire tread materials, rather than individual rubbers, because of the lack of methods available for determining unknown average microstructure in environmental samples. ARTICLE HISTORY
... Dust from vehicle tyres (made of synthetic rubber, a hydrocarbon-based polymer), is increasingly acknowledged as a source of microplastics in air (Sommer et al., 2018;Kole et al., 2017;Wright and Kelly, 2017). Tyre abrasion products make up between 0.05 and 0.70 mg/m 3 of the ambient particulate matter 10 µm fraction (PM10) seen in studies across Japan, Europe and the USA (Unice et al., 2012;Panko et al., 2013); tyre wear particles also contribute significantly to man-made particles in the aquatic environment (Wagner, 2018). Abbasi et al. ...
Preprint
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Epidemiological studies assessing human uptake and potential effects following exposure to microplastics are scarce. In this review we draw together available toxicological data and information on human environmental exposure to provide a concise assessment of potential health implications of exposure to microplastics.
... IR-PHI Analysis of Road Dust. Road dust contains MNPs resulting from tire degradation 41,52 that are composed of natural 53 and synthetic rubbers 54,55 and nylon. 56 Synthetic rubbers are used to enhance tire cushioning and elasticity, 42 while nylon is used in tire inner liners. ...
... Most TRWP are emitted as nonairborne particles (90− 99.9%) 9 due to their size (4−120 μm) 4 and density (1−2 g cm −1 ). 10 Indeed, high concentrations of TRWP (100−100,000 mg kg −1 ) have been reported on roadside soil and in sediments (1000 mg kg −1 ) after transport by runoff water. 10 Therefore, involuntary ingestion of these particles by terrestrial and aquatic organisms may occur in the environment. ...
Article
Full-text available
Tire and road wear particles (TRWP) have been shown to represent a large part of anthropogenic particles released into the environment. Nevertheless, the potential ecological risk of TRWP in the different environmental compartments and their potential toxic impacts on terrestrial and aquatic organisms remain largely underinvestigated. Several heavy metals compose TRWP, including Zn, which is used as a catalyst during the vulcanization process of rubber. This study investigated the solubilization potential of metals from cryogenically milled tire tread (CMTT) and TRWP in simulated gastric fluids (SFGASTRIC) and simulated intestinal fluids (SFINTESTINAL) designed to mimic rainbow trout (Oncorhynchus mykiss) gastrointestinal conditions. Our results indicate that the solubilization of heavy metals was greatly enhanced by gastrointestinal fluids compared to that by mineral water. After a 26 h in vitro digestion, 9.6 and 23.0% of total Zn content of CMTT and TRWP, respectively, were solubilized into the simulated gastrointestinal fluids. Coingestion of tire particles (performed with CMTT only) and surrogate prey items (Gammarus pulex) demonstrated that the animal organic matter reduced the amount of bioavailable Zn solubilized from CMTT. Contrastingly, in the coingestion scenario with vegetal organic matter (Lemna minor), high quantities of Zn were solubilized from L. minor and cumulated with Zn solubilized from CMTT.
... Tire tread wears off with time due to friction with the road and the following tire debris subsequently combine with the road pavement particles to form the tire and road wear particles [7] . The effect of TRWP on air and water have been reported in many studies [8][9][10][11][12][13] . For instance, Maceira et al. [14] reported a 0.003% health risk (negative effect on the liver and kidneys and respiratory irritation) from derivatives of benzothiazole in atmospheric samples. ...
Article
The abundance of microplastics found in the environment is a major cause of concern. Tire tread particles containing additives such as curing accelerators and antioxidants, can be a major source of elastomer pollution in the environment. Such tire particles combined with road pavement particles are referred to as tire and road wear particles, TRWP. The environmental availability from parent elastomers and the release of additives in the process of abiotic degradation were evaluated using freeze-thaw, wet-dry and accelerated UV-weathering experiments. Acceleration factor determination tests were conducted to correlate UV-exposure to the natural aging in the environment. Freeze-thaw testing showed many additives such as diphenyl guanidine (DPG), benzothiazole sulfenamide (BTS) and para-phenylene diamine (6 PPD) as tetrahydrofuran leachates and BTS transformation products. Further, UV exposure equivalent to 1.5 yr., 3 yr. and 5 yr. aging resulted in the formation a combination of ketones and carboxylic acids for styrene butadiene rubber (SBR), natural rubber (NR), and butadiene rubber-based tire cryogrinds. Attenuated total reflectance- Fourier- transform infrared spectroscopy (ATR-FTIR) was used to detect the degradation of the elastomers on UV-exposure while gas chromatography-mass spectroscopy (GC-MS) was used as a nontargeted, suspect screening analysis technique. The degradation intermediates and leachates identified using GC-MS represents useful data for the life cycle analysis of the functional polymers and additives and their possibility of environmental release.
... It is known [1][2][3][4][5][6] that the growth of the vehicle fleet in large cities leads to an increased emission of pollutants due to exhaust gases from car engines, wear of tires, brakes and road surfaces. According to the results of studies [7][8][9][10][11], the mass of exhaust gases due to the introduction of more stringent environmental classes decreases annually, and the mass of emissions of wear products of tires, brakes and roadways increases air pollution in cities and negatively affects public health. Moreover, the most dangerous for the health of the population (finely dispersed rubber dust and volatile substances) belong to the wear products of automobile tires [12][13][14][15]. ...
Article
Full-text available
The article shows that the high environmental hazard of tires is caused not so much by the mass of pollutants of dispersed particles, but by the toxic properties of the materials used in their manufacture and the impurities contained in them. It is emphasized that when assessing the quality of automobile tires, there are no reliable indicators and methods that allow determining the level of their environmental hazard. The necessity of changing the regulatory requirements for assessing the quality of automobile tires by expanding the list of their environmental indicators, developing methods for controlling tire emissions, both at the production stages and during operation, is justified. A list of pollutants subject to regulation in the assessment of the environmental safety of automobile tires and methods of their measurement are proposed. The main pollutants subject to regulation and control are: benz(α)pyrene and other polycyclic aromatic hydrocarbons, as well as aromatic hydrocarbons and N-nitrosamines. The results of quantitative assessment of the composition and concentrations of harmful substances in the wear products of automobile tires are presented. The authors substantiate the level of rationing and methods that can be used in assessing the environmental hazard of automobile tires, both in the production process and in the conditions of their operation. It is proposed to use the principles of dose assessment of the toxicity of the total aerogenically absorbed dose of pollutants emitted in the wear products of automobile tires.
... TRWP size fractions PM10 and PM2.5 in urban areas(Panko et al 2013a; Panko et al,2019 ...
Technical Report
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The rubber tyre case study (RTC) is one of the case studies within the European NMBP13 projects, that are active in 2019-2023 with the development and establishment of a solid, well-balanced nano risk governance approach for Europe. The RTC investigates what can be learned from applying this nano risk governance approach to the problem of tyre wear generated by car driving activities. Within the frame of the NMBP13 project there is a special focus on the nanomaterials. As part of the RTC, this paper collects available risk-related scientific information about environmental release of tyre wear particles (TWP), which generally associates with road wear to form TRWP (Tyre and Road Wear Particles). The particles’ size distribution concerns coarse, micro-sized and nano-sized particles and its associates. Key questions concerned in this study are: ‘What are the risks of nanoparticles released during the use of rubber tyres?’ And if there are risks, how could these be controlled?
... Kole et al. (2017) estimate the global annual emission of particles from tires to be more than 3.3 megatons. Although partially retained by separate sewer systems in urban areas, approximately two thirds of these particles end up in soils via runoff or transport by air (Panko et al., 2013). Amounts of TPs in the soil vary a lot: depending on the distance from the road, transport dynamics and the traffic frequency, concentrations can range from 0.1 -117 g kg -1 (Baensch-Baltruschat et al., 2020;Wagner et al., 2018;Wik and Dave, 2009). ...
Preprint
Tire particles (TPs) are a major source of microplastic on land, and considering their chemical composition, they represent a potential hazard for the terrestrial environment. We studied the effects of TPs at environmentally relevant concentrations along a wide concentration gradient (0 - 160 mg g-1) and tested the effects on plant growth, soil pH and the key ecosystem process of litter decomposition and soil respiration. The addition of TPs negatively affected shoot and root growth already at low concentrations. Tea litter decomposition slightly increased with lower additions of TPs but decreased later on. Soil pH increased until a TP concentration of 80 mg kg-1 and leveled off afterwards. Soil respiration clearly increased with increasing concentration of added TPs. Plant growth was likely reduced with starting contamination and stopped when contamination reached a certain level in the soil. The presence of TPs altered a number of biogeochemical soil parameters that can have further effects on plant performance. Considering the quantities of yearly produced TPs, their persistence, and toxic potential, we assume that these particles will eventually have a significant impact on terrestrial ecosystems.
... During the tire use on the road, it will generate micronized rubber particles from abrasion, where they will mix with other materials and particulates deposited on the road (e.g. minerals, metals and salts) (Kreider et al., 2010;Unice et al., 2013;Kovochich et al., 2021). Estimates suggest that 10-17% of a tire is transferred into the environment as TWPs due to abrasion (Lassen et al., 2015;Unice et al., 2019aUnice et al., , 2019b. ...
Article
Full-text available
The interest in tire wear particles (TWPs), generated from abrasion of tires, have gained traction over the past few years, both in regards to quantifying particulate emissions, leaching of different compounds, toxicity, and analytical methods. The life of a tire, from cradle to end-of-life, crosses over different scenarios during its lifetime and transcends environmental compartments and legislative areas, underlining the need for a collective approach. Sustainability for a tire encompasses the use of raw materials, recycling of raw materials, circular economy and material sourcing. The tire industry is currently making significant efforts towards a greener and more sustainable production considering reduction of CO2-emissions, recycling, material sources and implementing the use of biomass from plants rather than oil-derived alternatives. In this paper, we aim to analyze and discuss the need for environmental regulation of tires in order to provide a series of targeted recommendations for future legislation. Our study shows that the numerous regulations related to tires focus on chemicals, manufacturing, raw materials, use of tires on roads, waste handling, safety and polycyclic aromatic hydrocarbons (PAHs) in different life cycle stages of a tire. However, none directly addresses the contribution of TWPs to the environment. Despite the overall good intentions of the existing regulations, there is a lack of focus on the compounds that partition from the tire and disperse in the environment, their mixture effects, and the transformative products from the parent compounds in the environment. Therefore, a renewed focus is needed on risk assessment of complex mixtures like TWPs. Thus, transparency in regard to use of chemicals in TWP, mixtures, minimization of emissions, and capture of particulate pollution should be a priority.
... Indeed, butadiene-styrene rubber constitutes 60% of tires in combination with natural rubbers and various additives [82]. Tire wear is a potential conspicuous source of MPs in urban environments [22], and Panko et al. [83] documented that nearly all (>99%) of the particles generated remain on the ground, accumulate in road dust [84], and are subsequently washed away by rainfall. Kole et al. [85] estimated that 5-10% of oceanic plastic in the oceans comes from tire degradation. ...
Article
Full-text available
The terrestrial environment is an important contributor of microplastics (MPs) to the oceans. Urban streams, strictly interwoven in the city network and to the MPs’ terrestrial source, have a relevant impact on the MP budget of large rivers and, in turn, marine areas. We investigated the fluxes (items/day) of MPs and natural fibers of Mugnone Creek, a small stream crossing the highly urbanized landscape of Florence (Italy) and ending in the Arno River (and eventually to the Tyrrhenian Sea). Measurements were done in dry and wet seasons for two years (2019–2020); stream sediments were also collected in 2019. The highest loads of anthropogenic particles were observed in the 2019 wet season (109 items/day) at the creek outlet. The number of items in sediments increased from upstream (500 items/kg) to urban sites (1540 items/kg). Fibers were the dominant shape class; they were mostly cellulosic in composition. Among synthetic items, fragments of butadiene-styrene (SBR), indicative of tire wear, were observed. Domestic wastewater discharge and vehicular traffic are important sources of pollution for Mugnone Creek, especially during rain events. The study of small creeks is of pivotal importance to limit the availability of MPs in the environment.
... 73 The abbreviation TRWP (tire-and road wear particles) also encompasses the combination of these sources from a range of urban environments. 75 A broad size range (10 nm to 10 μm) of laboratory generated TRWP has been measured ( Figure 1c,d), 76−82 with a unimodal mass distribution in the 1−7 μm range and number size distribution of 10−200 nm. On-road TRWP sampling and measurements on instrumented cars have adopted various approaches. ...
Article
Full-text available
Implementation of regulatory standards has reduced exhaust emissions of particulate matter from road traffic substantially in the developed world. However, nonexhaust particle emissions arising from the wear of brakes, tires, and the road surface, together with the resuspension of road dust, are unregulated and exceed exhaust emissions in many jurisdictions. While knowledge of the sources of nonexhaust particles is fairly good, source-specific measurements of airborne concentrations are few, and studies of the toxicology and epidemiology do not give a clear picture of the health risk posed. This paper reviews the current state of knowledge, with a strong focus on health-related research, highlighting areas where further research is an essential prerequisite for developing focused policy responses to nonexhaust particles.
... One of the major sources of MPs in the ocean (Siegfried et al., 2017;Sundt et al., 2014) are tyre wear particles (TWPs) and road wear particles (RWPs), which are generated during the mutual abrasion between tire and road surfaces (Jekel, 2019). Furthermore, when such particles combine by encrustation of rubber particles by mineral particles (RWPs), they form TRWPs, whose presence was reported in various environmental compartments, like atmosphere, soils, and surface waters (Baensch-Baltruschat et al., 2021;Klöckner et al., 2020Klöckner et al., , 2019Panko et al., 2013;Wik and Dave, 2009). Based on their physical and chemical properties TRWPs have recently been included in the definition of MPs (Baensch-Baltruschat et al., 2020). ...
Article
Full-text available
The microplastics (MP) pollution has been receiving high attention in recent years, because of the massive amounts of plastics it contributes to the environment. Tyre wear and road wear particles (TWP and RWPs) were identified as major sources of MPs, but the observed data on these particles in urban snow deposits and snowmelt is scarce. To contribute to remediation of this situation, a study designed to quantify TWPs and RWPs in urban roadside snowbanks, and assess the MP occurrence in three size fractions, was conducted in the Luleå and Umeå municipalities in Northern Sweden. TWPs and RWPs were determined in three size fractions: 50–100 μm, 100–300 μm, and ≥300 μm, and their release from melting snow was investigated in the laboratory under controlled conditions. Among the MPs identified in snow and the associated snowmelt samples, a majority consisted of both types of particles (T&RWPs) with an average of 20,000 ± 48,000 number/L, whereas other MPs (fibres, fragments, flakes, and films of plastic) were much less plentiful with an average concentration of 24 ± 16 number/L. The largest proportion of T&RWPs was detected in the size fraction 50–100 μm (around 80 %), and the smallest proportion was in the fraction ≥300 μm (about 2 %). Of the T&RWPs, about 85 % were black bitumen particles (RWPs), composed of bitumen, mineral material and polymer modifiers, and 15 % were tire wear particles (TWPs) composed of rubber. The laboratory snow melting experiments demonstrated that urban snow stored MPs, which were eventually released during snowmelt. The ultimate fate of released MPs would depend on snowmelt drainage; it may either drain away from the road pavement and infiltrate into the ground, or enter the road gutter and be conveyed to storm sewers discharging to the receiving waters.
... So far, MPs been detected in the air of urban and remote regions, with abundances/fluxes spanning several orders of magnitude across different sites [16,17,23,[29][30][31][32][33][34] as well as outdoor and indoor dusts [23,35,36]. Sources of atmospheric MPs have been primarily reported, such as plastic food package [37], vehicle exhaust [38][39][40], and emission from domestic laundry dryers [23,25,26,35,36,41,42]. ...
Chapter
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Microplastics (MPs) are ubiquitous in waters, sediments, organisms, and air, which has attracted serious attentions. This review of MPs in the air provides comprehensive presence of the MPs in indoor and outdoor atmospheric environments worldwide. In addition, this review also gives insight into partitioning of the airborne MPs in the atmospheric suspended particulates, fallouts, and dusts.
... There are many dispersion models applicable for exhaust emissions, but according to early research [23,32] , many things related to non-exhaust dispersion remain unknown. The University of California, Riverside (UCR) team is conducting an on-going project to understand the severity of non-exhaust emissions at nearer roads and is currently testing non-exhaust parameters in their existing dispersion model 5 . ...
Article
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This paper provides an agent-based model, entitled TRAPSim, to examine the exposure to non-exhaust emissions (NEEs) and the consequent health effects of driver and pedestrians groups in Seoul. To make the model reproducible and replicable, TRAPSim uses the ODD protocol to demonstrate the details of the agents and parameters, as well as provide the codes alongside the descriptions to avoid possible ambiguity. The model’s main parameters are thoroughly tested through sensitivity experiments and are calibrated with the city’s air pollution monitoring networks. This paper also provides the instructions to the model, possible artefacts, and the configurations to submit the model on the HPC cluster. •An ODD protocol is used to document the agent-based model TRAPSim •Sensitivity experiments and calibration are explained •The step-by-step codes and annotations are attached in the protocol and HPC sections
... tread contribution to PM 10 and 1-7% to PM 2.5 . Using pyrolysis-GC-MS, Panko et al. (2013) measured airborne TWPs in both urban and rural areas of the United States, France, and Japan. In this study, the chemical markers included butadiene and isoprene dimers specific to cross-linked natural rubber, as well as styrene-butadiene and butadiene polymers. ...
Article
Full-text available
Pollution derived from car tires is of growing research interest due to its apparent omnipresence in the urban environment and its associated toxicity. Studies have focused largely on the occurrence of these tire materials, deemed tire wear particles (TWPs), and their associated chemicals in the aquatic environment. However, less attention has been paid to atmospheric TWPs, which can remain airborne and be transported over long distances. In addition, there are few studies pertaining to the gaseous contaminants originating from tire wear, creating a significant knowledge gap. This review aims to summarize the current state of knowledge surrounding atmospheric tire wear pollution by detailing relevant studies conducted under both laboratory and ambient environmental conditions. Organic chemicals that are associated with this form of pollution, including diphenylamine antioxidants, phthalates, benzothiazole, benzotriazoles, and alkylphenols were highlighted for their potential implications for air. While a number of studies have investigated oxidation in aquatic environments, the current review highlights a clear absence of oxidation product information relevant to air. There is also a critical research gap surrounding the physico-chemical properties of these potential atmospheric pollutants. As a result, the environmental behaviour and fate of these contaminants are largely unknown. Based on these knowledge gaps, we propse recommendations for future work to advance this area of research.
Article
Plastic products, used in almost all aspects of daily life because of their low cost, durability, and portability, could be broken down into micro- and nano-scale plastics, thereby increasing the...
Article
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Growing natural calamities as a consequence of global warming are one of the most pondering subjects today. The exponential growth of environmental pollution due to unscientific human exploitation of natural resources is considered the prime reason for the harsh responses of nature. Researchers from various fields of industry and academia are working hard to develop and implement products/technologies that are environmentally friendly or less harmful to the ecosystem. Material researchers, specifically those working in the automobile sector are also not behind in search of green products from eco-friendly raw materials and production methods. The automobile industry is collectively responsible for around 40% of global pollution in terms of greenhouse gas emissions. Out of which around 20–30% is originating from tyre production and its end-use. In this view, tyre production from eco-friendly raw materials and technologies that have minimum hazardousness to the environment is a hot research topic today. A few products in the market with “green” tags and many are in the pipeline for the recent future. This review summarises a detailed discussion of the emerging green technologies for tyre production and depicted comprehensive data from the available literature. The paper has been drafted from a well-balanced academic and industrial point of view since the researchers from both sectors are working in harmony for a better future for green tyre technology.
Chapter
The extensive usage and mismanagement of plastics have contributed to the predominance of microplastics (MPs) and nanoplastics (NPs) in the environment. The primary sources of MPs and NPs for marine ecosystems are land-based, accounting for 80% of MPs in marine environments. Rivers and human activities are major pathways through which MPs and NPs get into larger water bodies like seas and oceans. Also, wind and natural events such as storms and hurricanes contribute to the mobility of MPs and NPs. The distribution patterns of MPs and NPs in marine ecosystems are influenced by the shape, density, biofouling, adsorption, and location. In marine ecosystems, MPs and NPs are transported vertically or horizontally based on the properties and features of the plastics as well as the ocean geometry and conditions. MPs have been detected in the sediments and surface waters of various countries in abundances ranging from 0.1 MPs Kg− 1 dry weight (dw) of sediments in Brazil to 5000 MPs Kg− 1 dw of sediments in Canada. The concentration of MPs in sediments varies based on the sources or how MPs are cycled. Because of the toxicity and abundance of MPs and NPs, it is imperative to understand their fate, interaction, transport, and impact on the environment; their tiny sizes ranging from 0.1 μm to 5 mm allow MPs and NPs to be easily transported through oceans, trophic levels, and animal tissues. MPs and NPs are ubiquitous in the marine environment and can adversely affect aquatic animals and instigate inflammation, starvation, chemical intoxication, reduced fertility, and even death. MP and NP pollution will likely increase in the future because of the high demand and production of plastic products. Therefore further research is needed to understand the fate, transport, and environmental impacts of NPs and MPs. In addition, because of the growing rate of plastic pollution in the environment and the adverse effect of MPs and NPs on biota and the environment, preventive measures are needed to reduce the abundance of MPs and NPs.
Article
The abrasion behavior of model tire tread compounds was characterized by the shapes and size distributions of their wear particles. Carbon black-filled NR/BR vulcanizates with varying compositions (NR/BR = 100/0, 80/20, and 60/40) were used. These were thermally aged at 80 °C for 30 days. The wear particles produced from the aged specimen had rougher shapes than those produced from the unaged specimen. The size distributions of wear particles for the aged specimen were smaller than those for the unaged specimen. The wear particles produced from the NR = 100 sample had a larger size distribution than those produced from the NR/BR blend samples. The size distributions of wear particles smaller than 500 μm were found to be closely related to the crosslink density irrespective of the rubber composition and thermal aging. The aged samples exhibited narrower abrasion patterns than their unaged samples. Furthermore, the spacing and depth decreased as the BR content increased. The abrasion patterns were closely related to the size distributions of wear particles. The abrasion rates and the number of wear particles significantly increased after the thermal aging. The abrasion behavior was mainly affected by the crosslink density, rubber composition, presence of antidegradants, and tensile strength. By analyzing the shapes and size distributions of the wear particles and the crosslink densities, the abrasion behavior could be further elucidated.
Article
Tire wear particles (TWPs) are considered to be one of the major sources of microplastics (MPs) in sewers; however, little has been reported on the surface properties and photochemical behavior of TWPs, especially in terms of their environmental persistent radicals, leachate type, and response after photoaging. It is also unknown how TWPs influence the production of common pollutants (e.g., sulfides) in anaerobic biofilms in sewers. In our study, the effects of cryogenically milled tire treads (C-TWPs) and their corresponding photoaging products (photoaging-TWPs, A-TWPs) on anaerobic biofilm sulfide production in sewers and related mechanisms were studied. The results showed that the two TWPs at a low concentration (0.1 mg L⁻¹) exerted no significant (p > 0.05) effects on sulfide yield, whereas exposure to a high concentration of TWPs (100 mg L⁻¹) inversely affected sulfide yield, with A-TWPs exerting a significant inhibitory effect on sulfide yield in the sewers (p < 0.01). The main reason was that A-TWPs carried higher concentrations of reactive environmental persistent radicals on their surfaces after photoaging than C-TWPs, which could induce the formation of oxygen radicals. In addition, A-TWPs were more uniformly distributed in the wastewater system and could penetrate the biofilm to damage bacterial cells, and their ability to leach polycyclic aromatic hydrocarbons and heavy metals such as zinc additives enhanced their toxic effects. In contrast, C-TWPs contributed significantly to sulfide production (p < 0.01), primarily because of their low biotoxicity, ability to leach a considerable amount of sulfide, and stimulatory effect on anaerobic biofilm surface sulfate-reducing bacteria. Our study complements the toxicity studies of the TWPs particles themselves and provides insight on a new influencing factor for determining the changes in sulfide generation and control measures in sewers.
Article
In general, tire tread rubber compounds contain oleamide for improvement of manufacturing processibility, mold release characterization, and abrasion resistance. Tire tread wear particles (TWPs) are one of major contributors to microplastic emissions. In this study, a novel analytical method for quantification of TWP in microparticles produced on the road (road dust, MPRs) was developed by employing oleamide as a new marker. MPRs were collected at bus stops in autumn, winter, and summer seasons. MPRs of 38–63, 63–106, 106–212, and 212–500 μm obtained by size separation were employed for the analysis. Rubber components for bus and passenger car tire tread compounds were identified using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Oleamide was extracted from the MPRs with acetone and was identified using GC/MS. The oleamide concentration was analyzed using GC equipped with flame ionization detector (FID). The TWP contents of the MPRs were determined using the oleamide concentrations and the reference compound formulations. In order to reduce the sampling errors, each experiment was carried out five times and the results were averaged. The TWP contents of the MPRs were 1.4–4.7 wt% and were different according to the sampling seasons and places. The TWP contents were increased by increasing the traffic volume and the temperature.
Article
The share of non-exhaust particles, including tire wear particles (TWP), within the airborne dust and particularly within PM10 has increased in recent years due to a significant reduction of other particles including exhaust road traffic emissions. However, the quantification of TWP is a demanding task due to the non-specificity of tracers, and the fact that they are commonly contained in analytically challenging low concentrations (e.g. Zn, styrene, 1,3-butadiene, vinylcyclohexene). This difficulty is amplified by the chemical and morpho-textural heterogeneity of TWP resulting from the interaction between the tires and the road surface. In contrast to bulk techniques, automated single particle SEM/EDX analysis can benefit from the ubiquitous heterogeneity of environmental TWP as a diagnostic criterion for their identification and quantification. For this purpose, we follow a machine-learning (ML) approach that makes use of an extensive number (73) of morphological, textural (backscatter-signal based) and chemical descriptors to differentiate environmental particles into the following classes: TWP, metals, minerals and biogenic/organic. We present a ML-based model developed to classify airborne samples (trained by >100,000 environmental particles including 6841 TWP), and its application within a one-year monitoring campaign at two Swiss sites. In this study, the mass concentration of TWP in the airborne fractions PM80-10, PM10-2.5 and PM2.5-1 were determined. Furthermore, the particle size distribution and shape characteristics of 5620 TWP were evaluated. A cut through a TWP by means of FIB-SEM evidences that the mineral and metal particles typically found in TWP are not only present on the particle surface but also throughout the complete TWP volume. At the urban background site, the annual average mass fraction of TWP and micro-rubber in PM10 was 1.8% (0.28 μg/m³) and 0.9%, respectively. At the urban kerbside site, the corresponding values were 6 times higher amounting to 10.5% (2.24 μg/m³) for TWP, and 5.0% for micro-rubber.
Article
Transferable and reliable methods for tire and road wear particles (TRWP) environmental mass quantification are needed for environmental risk assessment. The comparative performance of three pyrolysis-gas chromatography-mass spectroscopy (Py-GC-MS) technologies with internal standard was assessed for pure polymers and three cryomilled tire tread (CMTT) samples with or without a standard artificial sediment matrix following ISO Technical Specification (TS) 21396:2017. The pyrolyzer technologies included Curie Point (CP; ferromagnetic induction), microfurnace (MF; ceramic heater), and resistive (R; platinum filament). The dimeric pyrolysis markers for tire tread polymer included: 4-vinylcyclohexene (4-VCH), a marker for styrene-butadiene rubber (SBR) and butadiene rubber (BR); dipentene (DP), a marker for natural rubber (NR) or isoprene; and 4-phenylcyclohexene (4-PCH), a marker specific to SBR not considered in the ISO TS. Comparing the performance of three pyrolysis technologies for quantifying six samples (two tread amount levels for three formulations), the average relative standard deviation in pure-CMTT measured in triplicate using 4-VCH and DP was 6.8% (MF), 26% (CP), and 60% (R) without matrix (100 or 1000 ug CMTT), and 19% (MF), 26% (CP) and 105% (R) with matrix (0.5% or 5% CMTT). The recovery of CMTT was greater than 50% for all MF and CP samples with good separation at the two amount levels. An increased frequency of CMTT recoveries >150% for MF and CP artificial sediment analysis suggests future consideration of pre-treatment (e.g., thermal desorption or labile organic digestion) in addition to the previously identified importance of polymer microstructure. The magnitude of variability observed with the resistive instrument indicates that further method development may be necessary to optimize thermal transfer. Overall, Curie point and microfurnace were found to be excellent candidate pyrolysis technologies for ongoing quantitative Py-GC-MS of TRWP in environmental method development, capable of a low likelihood of underestimating polymer mass with reasonable replicate precision.
Article
A comprehensive understanding of tire and road wear particles (TRWPs) and their detection and quantification in soils is still challenged by the lack of well-set standardized methods, inherent technological inconsistencies, and generalized protocols. Our protocol includes soil sampling, size separation, and organic matter removal by using hydrogen peroxide followed by density separation and analysis. In this context, roadside soil samples from different sites in Kansas and Ohio, USA, were collected and analyzed. Tire cryogrinds analogous to TRWPs were used to evaluate various density separation media, and collected particles more than 1 mm in size were then subjected to infrared spectroscopy (IR), thermogravimetric analysis (TGA), and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX) to confirm TRWP presence. Particles smaller than 1 mm were Soxhlet extracted, followed by gas chromatography–mass spectrometry (GC–MS) to validate the presence of tire-related intermediates. SEM-EDX validated the presence of elemental combinations (S + Zn/Na) ± (Al, Ca, Mg, K, Si) attributed to tires. Ketones, carboxylic acids, epoxies, cyclohexane, and benzothiazole sulfenamide (BTS) intermediates were the most probable tire-related intermediates observed in the roadside soil samples. Thus, this simple, widely applicable, cost-effective sample preparation protocol for TRWP analysis can assist TRWP research advancement in terrestrial environments.
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Freshwater sources have been contaminated with toxic and unwanted substances worldwide. Among these toxic substances, microplastics (MPs) are becoming prominent. There is already a debate on the impact of MPs on the aquatic environment. Tire and road wear particles (TRWPs) are a dominant group among MPs, and it is vital to estimate their occurrence in the environment. This study proposed a conceptual framework to estimate the occurrence and emissions of TRWPs in the environment. The proposed framework developed a vehicle emission model combined with a previously developed freshwater transport model and was demonstrated using a region in Okanagan Valley, British Columbia, as a case study. A sensitivity analysis was performed to address the uncertainty in TRWP emissions. Furthermore, scenarios were developed considering various environmental, management, and treatment factors to forecast the TRWP emissions under different situations. The total TRWPs emission estimated on the road ranged between 25 and 167 t/year, the estimated TRWPs emission to surface water ranged between 4 and 32 t/year, and the estimated TRWPs emission entering lakebed ranged between 4 and 23 t/year. Furthermore, the scenarios analysis showed that selected management and treatment strategies under given environmental conditions can reduce the total emission on-road (from >130 t/year to <60 t/year); reduce emission to surface water (from >35 t/year to ≈12 t/year); and reduce lakebed emissions (from 25 t/year to <8 t/year). Therefore, these management and treatment strategies could reduce the annual per-capita TRWP emissions from >4 kg/c/year to <2 kg/c/year. The proposed framework is flexible and can be adapted to forecast TRWP emissions in different regions. The developed model and framework can be improved by collecting more data and considering other contributing factors.
Article
Tire particles are generated by the abrasion of tire treads on roads and are major contributors to microplastics in soil environments. Contamination by tire wear particles worsens annually as the use of personal mobilities increases. Tire particles (112-541 µm) were obtained from three types of personal mobility tires (bicycle, car, and electric scooter) and exposed to plants (Vigna radiata) and springtails (Folsomia candida) for 28 d to assess the toxicity of each tire-particle type. The laboratory-generated tire particles exhibit adverse effects depending on the origin of the tire or test species. Particles from bicycle or electric-scooter tires changed the soil's bulk density and water holding capacity and adversely affected plant growth. Car tire particles had leached various organic compounds and induced detrimental effects on springtails (adult and offspring growth). We concluded that laboratory-generated tire particles (frow new tires) can affect the soil environment by changing soil properties and leaching chemicals; thus, causing adverse effects on soil organisms. Since this study found tire particle toxicity on soil organisms, it would be possible to compare the various contamination levels in areas near road soil and other clean soils.
Article
Tires generally wear out due to the friction between the tire and the road surface. Minimizing tire wear could reduce the non-exhaust particulate matter (PM) emissions from tires. Typically, tire treadwear grade can be used as an indicator of PM emissions from tires. Tires that wear out quickly will produce higher PM emissions than more durable tires. In this study, the effect of treadwear grade on the generation of tire PM emissions was investigated through laboratory and on-road driving measurements. In the laboratory measurements, a tire wear simulator installed in an enclosed chamber was used to eliminate artifacts caused by interfering particles during the generation and measurement of tire wear particles. For realistic on-road driving measurements, a mobile sampling vehicle was employed to sample road dust. The road dust was chemically analyzed using pyrolysis gas chromatography–mass spectrometry (GC–MS) to characterize the tire-road wear particles. Both measurements showed that the higher treadwear grade generated lower tire PM emissions due to the high strength of the rubber, except for the UTQG 700 tire. The UTQG 700 tire, which had the highest treadwear grade, produced higher PM emissions than the UTQG 350 and 500 tires because it readily formed the fine particles due to lamellar peeling rather than tearing or curling of tire treads. Notably, tire nanoparticles were observed in laboratory measurements due to the volatilization and nucleation of the sulphur (S) and zinc (Zn) compounds in the tire tread due to the frictional heat between the tire and paved road surface.
Article
Tire-derived particles and polyethylene (PE) debris co-exist in estuaries and potentially deteriorate water quality. Chemicals can be emitted from tire-derived particles and resorb to PE debris. However, there was lack of information about the interaction (e.g., sorption and desorption) between tire-derived chemicals and PE debris. By combining batch sorption and desorption experiments along with in situ field deployment of PE sheets, we examined the utility of benzothiazoles (BTZs) sorbed in PE as suitable markers of tire-derived inputs. The sorptive characteristics and PE-water partition coefficients (often designated as Kpew) of selected tire-derived marker candidates, i.e., polycyclic aromatic hydrocarbons (PAHs), benzothiophenes (BTPs) and BTZs, were measured. Moderately polar BTPs and BTZs (except for 2-(4-morpholinyl) benzothiazole) reached equilibrium within 2–8 days, compared to 20 days for nonpolar PAHs. The measure Kpew values and octanol-water partition coefficients of PAHs, BTPs and BTZs were linearly correlated with each other (r² > 0.80; p < 0.05). The desorption potentiality of PAHs and BTZs from tire particles is consistent with the hydrophilic properties of the target chemicals, while desorption ratios of BTZs and PAHs are 25–87% and <20%, respectively. Samplers with PE sheets as the sorbent phase were deployed in Hailing Bay, an urbanized estuary in South China, to measure concentrations of PAHs, BTPs and BTZs. Benzothiazoles sorbed in PE samples were associated with the massive utilization of automobile tires, while PAHs were linked to the boat maintenance facilities and BTPs were not detected in any tire particle and field PE samples. Therefore sorbed BTZs in PE can potentially serve as chemical markers of tire-derived inputs to estuaries.
Article
The switch to electric vehicles (EVs) has been incentivised by governments all over the world to reduce the use of fossil fuels and improve air quality. However, whether such a move could effectively lower the levels of pollutants as much as expected is still controversial. This study estimates the impact values of exhaust and non-exhaust emissions emitted from internal combustion engine vehicles (ICEVs) and their equivalent EVs from an economic-environmental perspective, expressed as monetary impact values, so as to ascertain the environmental effect of the switch to equivalent EVs from ICEVs. These monetary impact values were calculated according to the emission factors and damage costs of these pollutants. The results indicate that the particulate matter (PM) monetary impact values of equivalent EVs may exceed those of ICEVs, which depends primarily on the extent of regenerative braking and road type. The monetary impact values of total pollutants decrease for the move from diesel passenger cars to their equivalent EVs with 0% regenerative braking. For the conversion of petrol passenger cars to their equivalent EVs with 0% regenerative braking, however, the total monetary impact values increase on both urban and rural roads. These results can be useful for the economic-environmental assessment of vehicle exhaust and non-exhaust emissions.
Article
The environmental threat represented by tire and road wear particles (TRWPs) has highlighted the need for effective analytical strategies for their detection and quantitation in different matrices. To date, however, there is little consensus in the literature on how to obtain reliable data on TRWPs in environmental samples, which chemical marker should be used, and how analytical results can be correlated with the amount of particulate. This review compares the analytical strategies described in the literature from a critical point of view and outlines the most crucial aspects, giving an overview of the current knowledge and discussing the analytical challenges that need to be addressed. The literature highlights the critical role played by the selection of detection and quantitation markers, the variations in the formulation of the tires, the environmental degradation pathways of TRWPs components, and the effects of the sample matrix and composition on the analytical response.
Article
Recognising the challenges and limitations of current methodologies to predict highway runoff concentrations, this paper presents a novel approach based on the derivation of pollutant emission factors for twelve different types of vehicle. Published emission factor data and properties of differing vehicles types are combined with annual average daily traffic volume (AADT), highway characteristics and rainfall data to determine the pollutant distributions associated with differing highway and traffic types. In this paper, the method is applied to 126 sections of highway in the Greater London Borough of Enfield (United Kingdom; UK) and results are comparable with values reported in the literature. The approach is used to identify the level of AADT predicted to result in an exceedance of environmental quality standards (EQS), with results suggesting that runoff from highways experiencing AADT values as low as 5000 may require treatment prior to discharge to receiving waters. Future scenario analyses indicate that the impact of progressively replacing petrol and diesel vehicles with electric vehicles will have negligible impact on concentrations of zinc (Zn), copper (Cu), cadmium (Cd) and total suspended solids discharging from highway environments. The approach enables identification and ranking of urban highways in terms of their pollution runoff potential and provides an important support to users in prioritising locations for the installation of sustainable drainage options in order to protect receiving water environments.
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Anthropogenic particles at the micro- and nano-scale are posing risks to human health and the ecosystem. Engineered nanomaterials, micro- and nano-plastics, soot, road and tire wear are a few prominent examples of particles that are either intentionally manufactured or incidentally produced and released into the environment. Analytical developments in the past few decades have made possible to study particles in the micro- and nanoscale, however there is still no universal protocol of analysis and caveats exist in the use of the most prominent techniques. The task is challenging due to the large variety of particle properties and the complexity of environmental media. This review discusses a selected group of techniques most likely to play a key role in future monitoring activities and discuss recent developments and inherent shortcomings.
Chapter
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In most European countries environmental protection and limitation of pollution problems are the subject of numerous research and monitoring programs. In Romania, environmental protection issues connected to intense local pollution sources have been considered of particularly great importance, especially during the last decade.
Technical Report
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The present report forms the final report from a major research project within the Swedish National Road Vehicle Emission Research Programme EMFO, carried out during the period 2005-2008. The project was carried out in collaboration between IVL, Lund University, SLB analys and VTI. Within the project extensive data have been collected by a variety of methods for measuring, sampling and analysing the chemical composition of different fractions of airborne particulate matter, with emphasis on the PM10 fraction. Collected data originate from indoor measurements in controlled runs with a circular road simulator as well as ambient air measurements at both street and roof level in a variety of Swedish cities. Based on elemental (metals etc.) source profiles of various sources to the different particle fractions, derived from the literature or from measurements carried out within the project, several different receptor models (e.g. COPREM, PMF) were applied to the collected data to derive the contribution from exhaust, brake wear, tyre wear, road surface wear, long-range transport etc., to the measured concentrations of PM10 and other particle fractions in urban environments. An important result of the project is the evidence for the great importance of studded tyres for the high PM10 concentration levels that occur in many Swedish cities during winter and early spring. According to the controlled indoor experiments with the road simulator studded tyres give rise to ten times higher emissions of PM10 than non-studded (friction) winter tyres, while PM10 emissions caused by summer tyres is almost negligible
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Experimental methods for identifying particles generated from the wear of automobile tires and roadway asphalts have been developed. The methods have been employed on aerosols, collected with Berner low pressure cascade impactors, in Copenhagen and Risø and aerosols collected with medium volume samplers on two locations in Copenhagen. Furthermore the deposited particulate matter has been measured in soil near highways and at remote sites, and finally the ad-and absorbed particulate matter has been measured on plant leaves sampled in Copenhagen and at remote sites. Tire and bitumen particles constitute each about 5 wt-% of the collected suspended particulate matter in inner city air. The particle size distribution shows that 92 % of the mass of airborne particulate tire debris have aerodynamic diameters smaller than 1 µm. The mean aerodynamic diameter is about 1 µm for the bitumen particles.
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We performed intensive sampling campaigns of Hg0 fluxes over emergent macrophytes in the Florida Everglades to find a surrogate for Hg fluxes from water and vegetation to identifythe mechanisms of emission. We measured day time lacunal and sediment gas concentrations of Hg0, which suggested that the lacunal space acts as temporarystorage for Hg 0 and CH4. The absence of detectable Hg0 fluxes measured over uprooted (floating) plants and sediment incubation experiments suggest that the Hg0 emitted from emergent macrophytes such as Typha and Cladium originates in the sediment. HgII in the rhizosphere is reduced to Hg0 in these sediments byvarious processes, and is then transported bythe plants to the atmosphere bytwo separate processes. At night, Hg 0 and CH4 formed in the sediment accumulate in the lacunal space after crossing the root-sediment barrier. At sunrise, a form of pressurized through-flow purges the lacunal space of Typha into the atmosphere forming an earlymorning emission pulse for both gases, and coincidental peaks of CH 4 and Hg 0 suggest that the same lacunal gas transport mechanism is involved. Later in the daywhile the release of methane continues to deplete the lacunal pool, the Hg0 flux increases again to form a second peak in the afternoon when the CH4 emission has decreased. This peak parallels that of transpiration, and is presumablydue to xy lem transport of Hg 0 from continued production of Hg0 in the rhizosphere, perhaps in response to release of root exudates. A mass balance for this � 1500 ha wetland suggested that the total transpiration of Hg0 is � 1k g yr � 1 ,o r� 20 times the amount evaded from the water surface.
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Pyrolysis(pyr)-GC/MS analysis of characteristic thermal decomposition fragments has been previously used for qualitative fingerprinting of organic sources in environmental samples. A quantitative pyr-GC/MS method based on characteristic tire polymer pyrolysis products was developed for tread particle quantification in environmental matrices including soil, sediment, and air. The feasibility of quantitative pyr-GC/MS analysis of tread was confirmed in a method evaluation study using artificial soil spiked with known amounts of cryogenically generated tread. Tread concentration determined by blinded analyses was highly correlated (r2 ³ 0.88) with the known tread spike concentration. Two critical refinements to the initial pyrolysis protocol were identified including use of an internal standard and quantification by the dimeric markers vinylcyclohexene and dipentene, which have good specificity for rubber polymer with no other appreciable environmental sources. A novel use of deuterated internal standards of similar polymeric structure was developed to correct the variable analyte recovery caused by sample size, matrix effects, and ion source variability. The resultant quantitative pyr-GC/MS protocol is reliable and transferable between laboratories.
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Tire and bitumen particle concentrations are determined in aerosol and soil samples. They each constitute about 5 wt-% of the total suspended particulate matter (TSP) in inner city air, collected with a Berner low pressure impactor, 5 m from a road. The particle size distribution shows that 92% of the mass of airborne particulate tire debris have aerodynamic diameters smaller than 1 µm. The mean aerodynamic diameter is about 1 µm for the bitumen particles. This size range enables the possibility for far range transport and inhalation by humans. Soil concentrations in the vicinity of a highway indicate an approximate exponential decrease with increasing distance from the road. Constant values are reached after about 5 m for the tire particles and 10 m for the bitumen particles. Concentrations in soil that has not been touched for at least 30 years show a decrease in tire concentration by a factor of 30 when moving from the top soil to a depth of 3 cm. The bitumen concentration is approximately constant to a depth of 10 cm.
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Positive matrix factorization (PMF) method was applied to particle size-distribution data acquired during the Pittsburgh Air Quality Study (PAQS) from July 2001 to August 2001. After removing those days with nucleation events, a total of 1632 samples, each with 165 evenly-sized intervals from 0.003 to 2.5 μm, were obtained from scanning mobility particle spectrometer (SMPS) and aerodynamic particle sampler (APS). The temporal resolution was 15 min. The values for each set of five consecutive-size bins were averaged to produce 33 new size channels. The size distributions of particle number as well as volume were analyzed with a bilinear model. Three kinds of information were used to identify the sources: the number and volume size distributions associated with the factors, the time frequency properties of the contribution of each source (Fourier analysis of source contribution values) and the correlations of the contribution values with the gas-phase data and some composition data. Through these analyses, the sources were assigned as sparse nucleation, local traffic, stationary combustion, grown particles and remote traffic, and secondary aerosol in a sequence of decreasing number concentration contributions. Conditional probability function (CPF) analysis was performed for each source so as to ascertain the likely directions in which the sources were located.
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This study proposes a practical method to estimate elemental composition and distribution in order to attribute source and quantify impacts of aerosol particles at an urban region in Kolkata, India. Twelve-hour total particulates were collected in winter (2005-2006) and analyzed by energy-dispersive X-ray fluorescence technique to determine multi-elemental composition, especially trace metals. The aerosols consist of various elements including K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Se, and Pb which exhibit significant concentration at various sites (p < 0.05). The concentration of different metallic elements were found in the order of Zn > Pb > Ni > Cu > Cr > Co. Statistical multivariate analysis and correlation matrix analyses were performed for factor identification and consequent source apportionment. Contour profiles demonstrate spatial variation of elemental compositions indicating possible source contribution along with meteorological influences. Spatial differences were clearly most significant for Zn, Ni, Pb, and Cu reflecting the importance of anthropogenic inputs, primarily from automobile sources.
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To propose new molecular markers for tire-wear emissions, four dihydroresin acids, that is, 8-isopimaren-18-oic acid (I), 8-pimaren-18-oic acid (II), 13β(H)-abieten-18-oic acid (III), and 13α(H)-abiet-8-en-18-oic acid (IV), were identified and investigated for source specificities, distributions, and environmental stabilities. The absence of I-IV in natural sources and the linear correlations between dihydroresin acids with different skeletons in tires and in environmental samples demonstrated that I-IV are specific markers for synthetic rubbers. The ratio of III + IV to the sum of III + IV plus abietic acid showed the resin acids distribution between different environmental compartments receiving contributions from traffic and natural sources. The physicochemical properties and results of photolysis experiments suggested that I-IV can set lower limits for tire-wear contributions to environmental loads of particulate matter (PM) and polycyclic aromatic hydrocarbons with molecular weight ≥202. By comparing III + IV concentrations or (III+IV)/pyrene or (III+IV)/benzo[a]pyrene ratios in tires and those in environmental matrices, the contributions of tire-wear emissions to PM, pyrene, and benzo[a]pyrene were estimated to be 0.68 ± 0.54%, 6.9 ± 4.8%, and 0.37 ± 0.18% in roadside PM and 0.83 ± 0.21%, 0.88 ± 0.52%, and 0.08 ± 0.06% in rooftop PM.
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Recent studies have reported associations between particulate air pollution and daily mortality rates. Population-based, cross-sectional studies of metropolitan areas in the United States have also found associations between particulate air pollution and annual mortality rates, but these studies have been criticized, in part because they did not directly control for cigarette smoking and other health risks. In this prospective cohort study, we estimated the effects of air pollution on mortality, while controlling for individual risk factors. Survival analysis, including Cox proportional-hazards regression modeling, was conducted with data from a 14-to-16-year mortality follow-up of 8111 adults in six U.S. cities. Mortality rates were most strongly associated with cigarette smoking. After adjusting for smoking and other risk factors, we observed statistically significant and robust associations between air pollution and mortality. The adjusted mortality-rate ratio for the most polluted of the cities as compared with the least polluted was 1.26 (95 percent confidence interval, 1.08 to 1.47). Air pollution was positively associated with death from lung cancer and cardiopulmonary disease but not with death from other causes considered together. Mortality was most strongly associated with air pollution with fine particulates, including sulfates. Although the effects of other, unmeasured risk factors cannot be excluded with certainty, these results suggest that fine-particulate air pollution, or a more complex pollution mixture associated with fine particulate matter, contributes to excess mortality in certain U.S. cities.
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The prevalence and severity of latex allergy has increased dramatically in the last 15 years due to exposure to natural rubber products. Although historically this health risk has been elevated in hospital personnel and patients, a recent survey has indicated a significant potential risk for the general population. To obtain a wide-spread source for latex exposure, we have considered tire debris. We have searched for the presence of latex allergens in passenger car and truck tire tread, in debris deposited from the atmosphere near a freeway, and in airborne particulate matter samples representative of the entire year 1993 at two sites in the Los Angeles basin (California). After extraction of the samples with phosphate buffered saline, a modified-ELISA inhibition assay was used to measure relative allergen potency and Western blot analyses were used to identify latex allergens. The inhibition studies with the human IgE latex assay revealed inhibition by the tire tread source samples and ambient freeway dust, as well as by control latex sap and latex glove extracts. Levels of extractable latex allergen per unit of protein extracted were about two orders of magnitude lower for tire tread as compared to latex gloves. Western blot analyses using binding of human IgE from latex-sensitive patients showed a band at 34-36 kDa in all tire and ambient samples. Long Beach and Los Angeles, California, air samples showed four additional bands between 50 and 135 kDa. Alternative Western blot analyses using rabbit IgG raised against latex proteins showed a broad band at 30-50 kDa in all samples, with additional bands in the urban air samples similar to the IgE results. A latex cross-reactive material was identified in mountain cedar. In conclusion, the latex allergens or latex cross-reactive material present in sedimented and airborne particulate material, derived from tire debris, and generated by heavy urban vehicle traffic could be important factors in producing latex allergy and asthma symptoms associated with air pollution particles.
Article
Almost all the rubber materials in the highway sample originate from the vulcanized rubbers of automobile tire tread. This paper describes about a method of separation and determination of the vulcanized rubber in the particulate samples by pyrolysis-gas chromatography. Vulcanized rubber was extracted from a sample with ο-dichlorobenzene by destruction of bridge structure in a stream of oxygen at 180°C. Dissolution can be completed within 5 hours, and then, the solution was concentrated by evaporation. The pyrolysis gas chromatogram of the concentrated solution agreeded with that of the original vulcanized rubber; NR and SBR tire treads were determined by isoprene and styrene peaks in the chromatogram, respectively, using two calibration curves prepared with the standard compound of NR and that of SBR. The particulate samples were collected on a glass fiber filter by a high volume air sampler with a 10μm cut-off cyclone at the inlet of a highway tunnel (Iikura Tokyo). The sample size was 0.58 mg for each process. The average abundance ratios of NR and SBR tire tread rubber within the same piece of filter paper were 1.8% and 3.3%, respectively, and the total concentration of the tire tread rubber in the sample was 9.4 μg/m³. This procedure can be applicable to the samples of very small size, i.e. less than a few mg of a fraction of size distribution survey by an Andersen sampler. © 1977, The Japan Society for Analytical Chemistry. All rights reserved.
Article
In order to investigate on particulate matter emission and generation by the traffic of heavy-duty vehicles on roads, total suspended particulate matter (TSP) were collected at the roadside along major local-road Urawa-Tokorosawa with high-volume air samplers during September 14∼16 and November 30∼December 5, 1992. Concentration of tire-dust in TSP was determined by a method based on the determination of thiophene derivatives generated by the pyrolysis of TSP. During the latter sampling period, ambient concentrations of tire-dust generated by the traffic of heavy-duty vehicles and passenger cars were 1.8∼5.9 and 2.7∼6.0 μgm⁻³, respectively. These results suggest that 3-methylthiophene be a suitable indicator of TSP emitted and generated from heavy-duty vehicles, because it is a specific pyrolyzate from tire-dust for trucks and buses. Concentration of elemental carbon (EC), most of which could be emitted by diesel-powered vehicles. Contributions of total tire-dust by heavy-duty vehicles and passenger cars to TSP and EC concentration were ca. 4 and ca. 20%, respectively.
Conference Paper
A multivariate receptor model was applied to estimate the contribution of road traffic to ambient levels of fine particles (PM10) at different locations in Switzerland. At two roadside sites with heavy local traffic, the road traffic was found to account for 46% and 64% of PM10. At an urban background site, the estimated average road traffic contribution was 34%, whereas a slightly higher value was obtained at a suburban site (36%). These results are in agreement with the findings of a recent study, where a conceptually different approach (dispersion modelling) was applied.
Article
A study is reported which was undertaken to determine what happens to this tread material; whether or not the particulate matter remains airborne for long periods and hence constitutes an air pollutant in the usual sense. Extensive experimental data are presented and discussed. Airborne particulate matter worn from tires has been detected in the atmospheres of two vehicle tunnels and in the open air. The amount is about 20 per cent as great as that from vehicle exhausts, and represents a small fraction of the tread material that wears from tires. Tread rubber was found on tunnel walls and in roadside dust, dustfall, and topsoil. A material balance shows that most of the material lost by tires in service is particulate matter, of which only a small fraction is airborne.
Article
Each of the three analysis methods contributes to an understanding of the degradation processes which occur in environmentally exposed tire-wear particles. Extraction-pyrolysis-GC is the most reliable method since it treats the whole sample rather than a few particles. In 16 months, 52% of the polymer in tread-wear particulate was degraded in soil samples. In glass beads, only 36% of the polymer in tread-wear particulate degraded, perhaps because soil microorganisms were not available to degrade sulfur linkages in the vulcanized portion of the polymer. Fresh tread particles of the same size showed no degradation. The pyrolysis-GC results showed wider scatter, presumably because only a few rubber particles could be analyzed and all the particles did not degrade at the same rate. However, this method showed that the unsaturated bonds of polybutadiene undergo oxidative degradation more rapidly than do the aromatic bonds of styrene units. These results strongly suggest that one important mode of degradation of tread-wear paniculate is atmospheric oxidation. The TGA results showed that biodegradation did not reduce the total carbon content of the tread-wear particulate in this 16-month study. However, more than half of the extender oil was oxidized sufficiently to increase its vaporization temperature to the polymer temperature range. Biooxidation may have detoxified some of the polynuclear aromatic hydrocarbon portion of the oil. Overall, these results suggest that microbial attack of tread-wear particulate is less significant than attack by-atmospheric oxygen. To match the amount of rubber observed at the California freeway site, the removal rate by all mechanisms must be 0.67% per day. For this high removal rate, the amount of rubber at the roadside would reach a steady-state value within the first two years of a freeway's use at a level equivalent to five months of tire-wear. The rate of environmental degradation found in this study is 0.15 per day, or 22% of the total removal rate found in the California study. Wind erosion and water runoff probably also contribute to the total removal rate. Most importantly, we have shown that tread-wear particles degrade at a faster rate than tread-rubber itself, and that environmental degradation plays an important role in the fate of tire-wear particulate.
Article
An investigation is reported in which samples of airborne dusts were collected near heavily traveled highways and analyzed for rubber by pyrolysis gas chromatography. Dust samples obtained in truck traffic gave pyrolysis chromatograms markedly different from those obtained in passenger car traffic, and which correspond with those derived from known tire tread compounds. The distinction was based on the presence of styrene or dipentene in the pyrolyzates. Methods were developed for sampling atmospheric dusts and preparing small amounts in a form suitable for pyrolysis.
Article
Ambient dust was sampled with an Andersen high volume sizing impactor within twenty feet of heavy traffic on the Akron expressway and analyzed for tread rubber by pyrolysis gas chromatography. Methods were developed for removing dust particles from the collection surface and preparing them for pyrolysis. Those particles which lie in the respirable range 1.1 to 7.0 microns constitute 25 to 40% of the total by weight. The remainder is divided about equally between the size range above 7.0 μ (not respirable) and those below 1.1 μ, i.e., about one third of the dust lies in each size category. The amount of tread rubber in these respirable dusts as determined by styrene, dipentene, and vinylcyclohexene in their pyrolyzates varied from 1.5 to 9.2% with an overall average of 4.3%. In the size range above 7.0 μ a high value of 13.1% rubber was found with an average of 6.3%. In terms of micrograms per cubic meter of suspended particulates in the respirable range 1.1 to 7.0 μ, the values for tread rubber ranged from 1.0 to 4.9 with an average of 2.6. The low potential for health hazards from this respirable dust can be appreciated from a comparison with safe levels (TLVs) for certain pollutants known to be highly toxic as follows: Beryllium 2, lead compounds 150, mercury alkyls 10, cristobalite 50.
Article
Rubber particles emitted by abrasion of automobile tire tread have caused environmental pollution, and may be hazardous to our health. In this study, airborne particulate samples were collected on the glass fiber filter using high-volume air sampler at the roadside of the 2-nd Shinmei highway in Kobe. Rubber particles in the roadside atmosphere were analyzed by pyrolysis gas chromatography. The concentration of rubber particles was estimated from the total amount of styrene and isoprene, because these two compounds are pyrolysates of styrene butadiene rubber and natural rubber which are main materials for tires. These concentrations were 0.5-10.5 μg/m3, which corresponded to 0.4-6.3% of total airborne particulates. These concentrations were higher than those in other reports, because the sampling point was the roadside of the highway in this experiment. Furthermore quantitative and qualitative analyses of rubber additives (Zn-DMDTC and IPPD) in airborne particulates were carried out by HPLC, GC and MS. Zn-DMDTC, after converted into Co-DMDTC, in airborne particulates was analyzed by HPLC. The concentrations of Zn-DMDTC were 0-5.1 pg/m3. The detected amount of Zn- DMDTC did not show mutagenic activity. However, in the case of long term exposure to these tire tread particles, we must take a hazardous effect by Zn-DMDTC into consideration. On the other hand, IPPD was confirmed in none of samples by GC and MS.
Article
A multivariate receptor model was applied to estimate the contribution of road traffic to ambient levels of fine particles (PM<sub align="right"> 10 </sub>) at different locations in Switzerland. At two roadside sites with heavy local traffic, the road traffic was found to account for 46% and 64% of PM<sub align="right"> 10 </sub>. At an urban background site, the estimated average road traffic contribution was 34%, whereas a slightly higher value was obtained at a suburban site (36%). These results are in agreement with the findings of a recent study, where a conceptually different approach (dispersion modelling) was applied.
Article
A method for simultaneous determination of natural rubber (NR) and styrene-butadiene rubber (SBR) tire tread particles in atmospheric dust is described. Particulate rubbers are pyrolyzed at 740°C for five seconds in a Curie-point pyrolyzer. The resulting pyrolyzates are separated and detected by a gas chromatograph equipped with dual flame ionization detectors. Among several pyrolysis products, isoprene and styrene are chosen as indicator compounds for NR and SBR, respectively. The method is applied to a suite of atmospheric dust samples collected in Seoul, Korea by an Andersen sampler and some analytical results are presented.
Article
The Mohave Valley region of southern Nevada/southwestern Arizona has experienced elevated particulate concentrations and is classified as a PM10 nonattainment area. Anthropogenic aerosol sources in the area include the Mohave Power Project (MPP), a 1,580-MW coal-fired power plant; motor vehicles; construction activities; and paved and unpaved road dust and disturbed desert soil. Aerosols may also be transported long distances from other areas, such as the Los Angeles Basin. Based on the infrequency of plume contact at sites in the valley (as determined by SO2 measurements), it was believed that the contribution of the MPP to primary PM10 was minimal and that fugitive dust was the primary source of ambient particulate matter.To evaluate the magnitude of source contributors, PM10 measurements were made using a medium-volume sampler along with ancillary meteorological and air quality measurements in the Mohave Valley at Bullhead City, Arizona, for a period of longer than one year (September 1988 through mid-October 1989). The aerosol filter samples were analyzed for mass, elements, ions, and carbon. Source apportionment using the Chemical Mass Balance (CMB) receptor model was performed. On average, geological dust was the major contributor to PM10 (79.5%), followed by primary motor vehicle sources (16.7%), secondary ammonium sulfate (3.5%), secondary ammonium nitrate (0.1%), and primary coal-fired power plant emissions (0.1%).
Article
A method of simply and quickly determining styrene-butadiene (SBR) and isoprene (NR) tire tread rubbers in piled particulate matter on a highway was investigated.The particulate matter was analyzed with a gas chromatograph to which a Curie-point pyrolyzer was attached. The contents of the SBR and NR tire tread rubbers in the piled particulate matter were determined by measuring the generated amount of styrene and dipentene (1-methyl-4-isopropylcyclohexene) attributed to the respective rubber polymers contained in the matter, and the calibration curves of the amounts of the standard tire tread rubbers plotted against the peak areas of styrene and dipentene generated by the pyrolysis. The pyrolysis of the rubber polymers was conducted at 590° C for 5 seconds.The average contents of SBR tire tread rubber in piled particulate matter collected on the inside and outside of a tunnel on the highway were 0.0675–0.0920 and 0–0.0653 wt.%, respectively, and those of NR tire tread rubber were 0.127–0.176 and 0–0.100 wt.%.
Article
This paper is directed to air pollution scientists interested in special mobile emission sources. The purpose was to determine the contribution which automobile tires make to air pollution. The gaseous hydrocarbon and sulfur compounds emitted in laboratory tests were identified. Although these hydrocarbons can participate in smog reactions, their mass emission rate is less than 0.1 % of the current exhaust hydrocarbon emission rate. Hydrocarbons from tires are not measurable near a freeway. The particulate emitted from tires ranges in size from 0.01 μm to more than 30 μm, with the larger particles dominating the total mass. Measurements along a California freeway showed that most of the tire debris had settled within 5 m of the pavement edge. Airborne rubber concentrations were less than 0.5 μg/m, or less than 5% of the total tire wear. These field measurements confirm the indoor emission pattern and verify that tire wear products are not a significant air pollution problem.
Article
More than 100 organic compounds are quantified in these samples, including n-alkanes, n-alkanoic acids, n-alkenoic acids, n-alkanals, n-alkanols, benozoic acids, benzaldehydes, polyalkylene glycol ethers, PAH, oxy-PAH, steranes, hopanes, natural resins and other compound classes. Paved road dust acts as a repository for vehicle-related particles, which can then be resuspended by the passing traffic. To evaluate the contributions from major urban sources to the road dust complex, source profiles representing different types of vehicle exhaust, brake dust, tire debris, and vegetative detritus are compared, and their fractional contributions are estimated using several groups of organic tracer compounds. -from Authors
Article
As an indicator of tire wear debris and road dust, 2-(4-morpholinyl)-benzothiazole (24MoBT) was determined in environmental samples collected from urban Tokyo in 1989 and 1993/94. 24MoBT existed in tire tread rubber, road dust, runoff particles, river water particles, river sediment and aerosols in the widely varying concentrations (∼ng g-1 to ∼μg g-1). Comparison of 24MoBT concentrations in tire tread with those in environmental samples showed that tire debris were a significant component of ambient particulate matter. The contribution of tire debris to runoff was greatest during the early and middle stages of storms. Comparison of 24MoBT concentrations in road dust samples and river samples collected in 1993/94 showed that road dust may comprise as much as 28-65% of suspended river particles during storm-flow and 5.5-41% of river sediments.
Article
The concentration of tire tread in suspended particulate matter (SPM) was measured by a new method based on benzothiazole generated by pyrolysis of vulcanization accelerator. The variation of production yields of benzothiazole was examined for 24 kinds of tire treads currently used in Japan Pyrolysis was carried out at 670°C using a Curie-point pyrolyzer.The vertical profile and diurnal pattern of tire tread were investigated with 4-h samples continuously collected for 24 h at a heavy traffic density area in Tokyo. The diurnal percentage of tire tread in SPM at the sampling site of 86 m height showed two peaks following the trend of traffic density throughout the day. The concentration of tire tread collected at the 86 m level was about 30% of that at the 0 m level during the daytime. The seasonal variation of concentration of tire tread in SPM was measured at the sampling site located 20 km SW of Tokyo. The weight percentage of tire tread in SPM varied between 1.3 and 3% in winter with NE-NW wind and varied between 0.5 and 1.5% in spring with SE-SW wind.
Article
Atmospheric PM pollution from traffic comprises not only direct emissions but also non-exhaust emissions because resuspension of road dust that can produce high human exposure to heavy metals, metalloids, and mineral matter. A key task for establishing mitigation or preventive measures is estimating the contribution of road dust resuspension to the atmospheric PM mixtur