Tire Wear Research Articles

Incremental progress or dangerous incrementalism? The case of tire wear pollution in global environmental governance

ABSTRACT Tire wear and tear is among the largest sources of global microplastic pollution. Interviews conducted in 2024 appear to indicate ‘incremental progress’ toward improving governance of tire wear. Knowledge of the ecological and health consequences is increasing. Pressure is growing for greater producer responsibility. Global standards to limit tire abrasion are forming. Regulations are being implemented to address chemical contamination, such as in California. And some manufacturers are supporting higher standards and reengineering tires to undercut competitors and capture emerging markets for lower-abrasion tires. Yet, as a deeper analysis reveals, regulations remain highly uneven, piecemeal, and inadequate on a global scale, with new risk-taking as firms delay actions and introduce new chemicals as ‘solutions.’ Moreover, I argue, a ‘dangerous form of incrementalism’ is taking hold, where modest changes to state policy and corporate conduct are conferring legitimacy on governance processes unable to prevent tire wear pollution from escalating globally.

Comparison of reference libraries for the detection of tire-derived microplastics (TMPs)

ABSTRACT Introducing microplastics (MPs) into the marine environment is a global problem. Tire-derived microplastics (TMPs) are estimated to account for 60% of all secondary MPs dispersed in aquatic environments. To effectively detect TMPs in environmental samples using micro-Fourier transform infrared (μFTIR) spectroscopy, a high-quality reference library is essential. However, the use of conventional diamond crystals in FTIR presents challenges for the detection of materials containing carbon black, such as rubber and tires. In addition, there is a discrepancy between spectra from standard libraries and spectra from environmental samples, which makes detection difficult. In order to overcome these problems in the detection of TMPs by μFTIR, we developed four reference libraries to improve the detection, and ‘The 26 tire wear library’ was found to be the best among these four. Furthermore, a comparison of these new libraries revealed the following requirements to improve TMP detection: (i) the reference spectra must be acquired under the same setup used for material observation including prism material, (ii) tires, not rubber, must be used as reference materials, and (iii) tire wear samples must be prepared to replicate the actual generation conditions on roads.

Composition and concentrations of microplastics including tyre wear particles in stormwater retention pond sediments

Composition and concentrations of microplastics including tyre wear particles in stormwater retention pond sediments

Characteristics of pollutants emitted by motor vehicles and their impact on the environment and engine operation

Gaseous and solid pollutants (dusts) of atmospheric air have been defined. Dusts have been divided according to various criteria and their properties have been given. The sources and characteristics of anthropogenic and natural pollutants of atmospheric air have been presented. It has been shown that the main sources of anthropogenic pollutants, apart from industry, are motorization, and internal combustion engines of cars are a source of gaseous pollutants and solid particles, the emission of which has been significantly reduced. The originality of the article consists in conducting an extensive literature analysis and proving that the emission of "non-engine" pollutants in the form of dust from the wear of friction linings of brakes, clutches and from the wear of tires and roads, as well as mineral dust raised from the ground, is currently a greater threat to human health and the environment than engine emissions. The impact of particulate matter emissions from road transport and mineral dust, which is the basic component of road dust, on human health, vegetation and on the operation of engine and vehicle systems is presented.

Compound Class-Specific Temporal Trends (2021–2023) of Tire Wear Compounds in Suspended Solids from Toronto Wastewater Treatment Plants

Compound Class-Specific Temporal Trends (2021–2023) of Tire Wear Compounds in Suspended Solids from Toronto Wastewater Treatment Plants

All black: a microplastic extraction combined with colour-based analysis allows identification and characterisation of tire wear particles (TWP) in soils

While tire wear particles (TWP) have been estimated to represent more than 90% of the total microplastic (MP) emitted in European countries and may have environmental health effects, only few data about TWP concentrations and characteristics are available today. The lack of data stems from the fact that no standardized, cost efficient or accessible extraction and identification method is available yet. We present a method allowing the extraction of TWP from soil, performing analysis with a conventional optical microscope and a machine learning approach to identify TWP in soil based on their colour. The lowest size of TWP which could be measured reliably with an acceptable recovery using our experimental set-up was 35 µm. Further improvements would be possible given more advanced technical infrastructure (higher optical magnification and image quality). Our method showed a mean recovery of 85% in the 35–2000 µm particle size range and no blank contamination. We tested for possible interference from charcoal (as another black soil component with similar properties) in the soils and found a reduction of the interference from charcoal by 92% during extraction. We applied our method to a highway adjacent soil at 1 m, 2 m, 5 m, and 10 m and detected TWP in all samples with a tendency to higher concentrations at 1 m and 2 m from the road compared to 10 m from the road. The observed TWP concentrations were in the same order of magnitude as what was previously reported in literature in highway adjacent soils. These results demonstrate the potential of the method to provide quantitative data on the occurrence and characteristics of TWP in the environment. The method can be easily implemented in many labs, and help to address our knowledge gap regarding TWP concentrations in soils.

Predicting the Wear Amount of Tire Tread Using 1D-CNN.

Since excessively worn tires pose a significant risk to vehicle safety, it is crucial to monitor tire wear regularly. This study aimed to verify the efficient tire wear prediction algorithm proposed in a previous modeling study, which minimizes the required input data, and use driving test data to validate the method. First, driving tests were conducted with tires at various wear levels to measure internal accelerations. The acceleration signals were then screened using empirical functions to exclude atypical data before proceeding with the machine learning process. Finally, a tire wear prediction algorithm based on a 1D-CNN with bottleneck features was developed and evaluated. The developed algorithm showed an RMSE of 5.2% (or 0.42 mm) using only the acceleration signals. When tire pressure and vertical load were included, the prediction error was reduced by 11.5%, resulting in an RMSE of 4.6%. These findings suggest that the 1D-CNN approach is an efficient method for predicting tire wear states, requiring minimal input data. Additionally, it supports the potential usefulness of the intelligent tire technology framework proposed in the modeling study.

Trends and risk assessment of heavy metals in the surface sediments of river-connected lakes: A case study of Dongting Lake

This study analyzed the spatiotemporal distribution characteristics, ecological risks, biological toxicity, and sources of Cu, Zn, Pb, Cd, Hg, and As in the surface sediments of Dongting Lake, as well as the response of benthic macroinvertebrates to these pollutants. Among the three lake regions, the concentration of Cu, Zn, Pb, Cd, and As fell in the order of South Dongting Lake (SD) > East Dongting Lake (ED) > West Dongting Lake (WD), whereas the concentration of Hg fell in the order of WD > SD > ED. The concentrations of Cu, Zn, Pb, and As were 1.69–2.02 times the background values recorded in 1986, whereas the concentrations of Cd and Hg were 8.97 and 5.32 times the background values, respectively. The ecological risk was low for Cu, Zn, Pb, As but high for Hg and Cd. For Dongting Lake in aggregate, the heavy metals caused considerable ecological risk and high biotoxicity, although the situation was improving in recent years. Cd, As, Cu, Pb, Hg were mainly from agricultural sources, mining sources, tire wear and agricultural sources, industrial smelting and mining sources, industrial processing and smelting sources, respectively, and Zn was from mixed sources. A total of 66 species of benthic macroinvertebrates were identified from the sediments. From 2018 to 2022, the dominant benthic macroinvertebrates gradually shifted from the pollution-resistant in Tubificidae to those in Gammarus, Bellamya, Valvatidae, etc. Oligochaetes and Stictochironomus spp. exhibited extremely high response to heavy metals and could serve as indicator organisms of heavy metal pollution.

Tire wear monitoring using feature fusion and CatBoost classifier

Addressing the critical issue of tire wear is essential for enhancing vehicle safety, performance, and maintenance. Worn-out tires often lead to accidents, underscoring the need for effective monitoring systems. This study is vital for several reasons: safety, as worn tires increase the risk of accidents due to reduced traction and longer braking distances; performance, as uneven tire wear affects vehicle handling and fuel efficiency; maintenance costs, as early detection can prevent more severe damage to suspension and alignment systems; and regulatory compliance, as ensuring tire integrity helps meet safety regulations imposed by transportation authorities. In response, this study systematically evaluates tire conditions at 25%, 50%, 75%, and 100% wear, with an intact tire as a reference, using vibration signals as the primary data source. The analysis employs statistical, histogram, and autoregressive–moving-average (ARMA) feature extraction techniques, followed by feature selection to identify key parameters influencing tire wear. CatBoost is used for feature classification, leveraging its adaptability and efficiency in distinguishing varying wear patterns. Additionally, the study incorporates feature fusion to combine different types of features for a more comprehensive analysis. The proposed methodology not only offers a robust framework for accurately classifying tire wear levels but also holds significant potential for real-time implementation, contributing to proactive maintenance practices, prolonged tire lifespan, and overall vehicular safety.

Persistent Environmental Injustice due to Brake and Tire Wear Emissions and Heavy-Duty Trucks in Future California Zero-Emission Fleets.

The adoption of zero-emission vehicles (ZEVs) offers multiple benefits for the climate, air quality, and public health by reducing tailpipe emissions. However, the environmental justice implications of the nonexhaust emissions from future ZEV fleets for near-roadway communities remain unclear. Here, we model the on-road fine particulate matter (PM2.5) emissions across all California counties and assess the near-roadway exposure disparities at the census block group level in the Los Angeles County in 2050, when almost all passenger vehicles are projected to be ZEVs. We found that promoting zero-emission heavy-duty trucks generates more air quality benefits for disadvantaged communities than light-duty passenger vehicles. Persistent disparities in near-roadway PM2.5 levels, however, exist due to the remaining brake and tire wear emissions and increased truck traffic in disadvantaged communities. We recommend implementing fleet-specific ZEV policies to address brake and tire wear emissions and optimizing freight structures to address these persistent environmental justice issues in California.

Tire wear particles enhance horizontal gene transfer of antibiotic resistance genes in aquatic ecosystems

Microplastics (MPs) have introduced new surfaces for biofilm development and gene exchange among bacteria. We investigated Tire Wear Particles (TWPs) for their involvement in horizontal gene transfer (HGT), particularly in relation to associated metals in the matrices of TWPs. We employed red-fluorescently tagged E. coli strain as a donor with green-fluorescently tagged, broad-host-range plasmid pKJK5, resistant to trimethoprim. As a recipient, we utilized Pseudomonas sp. and a natural lake microbial community. HGT activity on TWPs was determined and compared with that on polystyrene (PS) (with and without metals), and chitosan, which was used as a natural surface. Exposure to TWPs significantly enhanced HGT frequency of antibiotic resistance gene (ARG) from donor to recipient compared to PS and chitosan, and metals of TWPs further promoted HGT. HGT frequency on TWPs with Pseudomonas sp. was found to be 10−3 at 30 °C. in the lake community, it was similarly high already at 25 °C suggesting a higher permissiveness of the natural microbial community towards ARG at lower temperatures. This study sheds light on the potential impact of TWPs in promoting HGT, forming the basis for health risk assessments of TWPs and more generally of MP pollution in various aquatic ecosystems.

Health benefits of US light-duty vehicle electrification: Roles of fleet dynamics, clean electricity, and policy timing

We present a dynamic perspective to quantify the air quality-related health impacts of the electrification of light-duty vehicles in the United States between 2022 and 2050. Using a fleet turnover model and future electricity generation mix scenarios, we compare ambitious vehicle electrification to fleet renewal relying on newer internal combustion engine vehicles, without electric vehicles. The model includes vehicle-level pollutant emission factors and a reduced complexity air quality and valuation model and covers direct (tailpipe, brake wear, and tire wear) and indirect (production of electricity and liquid fuels) emissions of NOx, SO2, PM2.5, NH3, and VOCs, with a breakdown at the county level to identify geographical disparities in the distribution of health impacts. Short-term health benefits are mostly generated by reductions in NOx emissions from newer gasoline vehicles, while fleet electrification generates further benefits in the long term. The electricity mix plays a crucial role in the success of electrification policies. With continued grid decarbonization, electrification would reduce harmful air quality-related health impacts cumulatively by 84 to 188 billion USD over the study period, compared with fleet renewal without electric vehicles. In contrast, artificially freezing the 2022 grid would make electrification responsible for 32 to 71 billion USD additional health disbenefits compared with fleet renewal. Finally, we show that while fleet electrification achieves most of its benefits over fleet renewal in the long term, delaying the implementation of such policies would sacrifice meaningful cumulative benefits.

Traffic Intensity as a Factor Influencing Microplastic and Tire Wear Particle Pollution in Snow Accumulated on Urban Roads

Traffic-related roads are an underestimated source of synthetic particles in the environment. This study investigated the impact of traffic volume on microplastic (MP) and tire wear particle (TWP) pollution in road snow. An examination was conducted in a medium-sized city situated in northeastern Poland, known for being one of the cleanest regions in the country. MPs and TWPs were found at all 54 sites, regardless of the intensity of traffic. The average concentration for all samples was 354.72 pcs/L. Statistically significant differences were found between the average values of the particle concentration on low, medium, and heavy traffic roads, amounting to 62.32 pcs/L, 335.97 pcs/L, and 792.76 pcs/L, respectively. Within all three studied groups of roads, MPs and TWPs with the smallest size, ranging from 50 to 200 μm, were prevalent. In all of the studied groups of roads, four analyzed shapes of particles were found, with irregular fragments being the most abundant form (89.23%). The most frequently recorded color among the collected samples was black (99.85%), and the least frequently recorded color was blue, constituting only 0.01%. This study suggests that snow cover on the roads may act like a temporary storage of pollutants during winter particularly in the temperate climate zone and, after thawing can significantly increase the concentration of MPs and TWPs in surface waters. Possible measures to decrease the release of MPs and TWPs into the environment in the city may include reducing the traffic volume and speed, implementing street sweeping, utilizing filtration chambers, and installing stormwater bioretention systems or settling ponds.

Carryover effects of tire wear particle leachate threaten the reproduction of a model zooplankton across multiple generations.

The toxic additives that leach from tire wear particles (TWPs) cause mass die-offs in fish and impact zooplankton as secondary consumers in the aquatic food web. In addition to the direct impacts of TWP leachate on a single generation, there may be potential delayed carryover effects across multiple generations from parental exposure, which may amplify the adverse effects of the leachate on individual reproduction and, consequently, on the entire population. In this study, the single, multiple, and transgenerational effects of TWP leachate at various concentrations on the reproduction and lifespan of the rotifer Brachionus calyciflorus were investigated. The results indicated that the lifespan and reproductive output of rotifers exposed to TWP leachate (0-1500 mg/L) decreased as the concentration increased above 250 mg/L. There was a clear multigenerational effect of TWP leachate on rotifer reproduction. The inhibition rates were consistently greater at 500 mg/L than at 250 mg/L leachate. Although the reproduction of rotifers exposed to 250 mg/L TWP leachate increased in the first two generations (P and F1), it was inhibited in subsequent generations. The inhibitory effect of 500 mg/L TWP leachate persisted across all generations, leading to population extinction by the F4 generation. A significant transgenerational effect of TWP leachate was found on reproduction. The adverse impact of exposure to 250 mg/L leachate for fewer than three generations could be reversed when offspring were transferred to clean media. However, this recovery was not observed after continuous exposure for more than four generations. Exposure to high-dose TWP leachate also caused irreversible damage to reproduction. Therefore, TWP leachate can result in cascading toxicity on zooplankton populations through carryover and cumulative effects on reproduction.

Typical Tire Additives in River Water: Leaching, Transformation, and Environmental Risk Assessment.

Tire wear particles (TWPs) released during vehicle driving can enter water bodies, leading to leaching of tire additives (TAs) in aquatic environments. However, the transformation behavior and related ecological impacts of TAs and their transformation products (TPs) remain unclear. In this study, laboratory-based simulation experiments and field investigations were conducted to explore the transformation mechanisms and ecological risks of TAs. After being placed in river water for 24 h, about 7-95% of 12 investigated TAs in TWPs were leached. Forty-eight TPs from eight TAs were tentatively identified along with different transformation pathways via suspect screening by high-resolution mass spectrometry. Semiquantitative results indicated that TPs derived from N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylene-diamine (6PPD) were predominant in leachates, while aryl hydrolysis and quinone pathways were the main transformation pathways. Field investigations on urban surface water samples from 16 sites in Hong Kong revealed the occurrence of 17 TAs and 1 TP, with concentrations ranging from 13.9 to 2230 ng/L (median ± standard deviation: 226 ± 534 ng/L). Sixteen TPs from six TAs were additionally identified via suspect screening. It is estimated that 6PPD-quinone and seven TAs could pose medium to high ecological risk, while N-(1,3-dimethylbutyl)-N'-phenyl-p-quinonediimine, a frequently detected TP, was identified as a persistent-bioaccumulative-toxic substance.

Field assessment of engineered bioretention as microplastics sink through site characterization and hydrologic modeling

Green stormwater infrastructure (GSI) practices like bioretention are considered a sink for microplastics washed in from urbanized land uses-land covers, and thereby regulating the environmental dispersion of microplastics. However, the capacity of GSI in microplastic sequestration remain unclear. This work investigated the spatial distributions of microplastics within bioretention cells and their soils, concentration in the GSI groundwater monitoring well, and the overall potential of GSI as a sink for microplastics. The average microplastic concentration in GSI soils (2718 - 3833 MPs/kg dry soil) is 7−10 times higher than background soils (262 - 520 MPs/kg dry soil). The most abundant microplastics observed were polypropylene (57 %), polyethylene (17 %), and rubber/bituminous (16 %), indicating the major sources of microplastics derived from post-consumer plastics and tire wear. Soils closest to the GSI stormwater inlet sequestered the most particles, and the microplastic concentration decreased with soil depth. Our hydrologic modeling, based on measured soil and hydraulic parameters, suggested that runoff overtopping the freeboard of the bioretention cell – and potentially dispersing microplastics into the surrounding environment – was unlikely. Microplastics in the GSI groundwater monitoring well was minimal at 11 MPs/L. These results suggest that GSI can capture and sequester microplastics to mitigate microplastic pollution in the environment.

Machine learning-driven intelligent tire wear detection system

Traditional methods detect wear by interpreting mathematical models and tire characteristics; however, these methods struggle to accurately reflect the actual rolling condition of the tire. In this study, we propose a machine learning-based tire wear detection module that can provide accurate results under tire test rig conditions. To develop this module, we designed three key components: integrated acceleration and PVDF sensors within the tire to capture vibration and deformation data; signal preprocessing algorithms to highlight multi-source signal differences under varying wear conditions; and deep learning algorithms to achieve precise tire wear grade identification. Experimental results demonstrate that, under different tire pressures, loads, speeds, and wear levels, the system can accurately identify tire wear grades with 99.99% accuracy by combining data from both sensors.

Co-Transport of Tire Wear Particles with Cd2+ and Ni2+ in Porous Media: Impact of Adsorption Affinity and Desorption Hysteresis

Co-Transport of Tire Wear Particles with Cd2+ and Ni2+ in Porous Media: Impact of Adsorption Affinity and Desorption Hysteresis

Microplastic contamination in Chinese topsoil from 1980 to 2050

China's soil is experiencing significant microplastic contamination. We developed a machine-learning model to assess microplastic pollution from 1980 to 2050. Our results showed that the average abundance of microplastics in topsoil increased from 45 items per kilogram of soil in 1980 to 1156 items by 2018, primarily due to industrial growth (39 %), agricultural film usage (30 %), tire wear (17 %), and domestic waste (14 %). During the same period, microplastic levels in cropland rose from 98 to 2401 items per kilogram of soil, and exposure levels for the Chinese population increased from 808 to 3168 items per kilogram. By 2050, a reduction in the use of agricultural films is expected to decrease cropland contamination by half. However, overall levels are anticipated to remain steady due to other persistent sources, indicating a continued spread of microplastics into subterranean environments, water bodies, and human systems. This study highlights China's microplastic challenges and suggests potential global trends, emphasizing the need for increased awareness and intervention worldwide.

Measurement of tyre-based microplastics using traditional and quantum cascade laser-based infrared spectrometry

BackgroundDespite the potential environmental impact of TWPs (tyre wear particles), there is a lack of reliable analytical methodologies suitable for their routineidentification and characterization. The number of papers dealing with this topic is, so far, very reduced and, therefore, there is a need for addressing it, mostly because traditional transmittance-based IR techniques are suboptimal due to scattering caused by black carbon in tyres. ResultsThis study aims to evaluate the most appropriate infrared (IR) spectrometric technique for monitoring TWPs. Macro attenuated total reflectance (ATR), reflectance microscopy, and quantum cascade laser-based micro transflectance (QCL-LDIR) were employed to analyse samples from used car and truck tyres in two sample configurations: small tyre fragments (∼1 cm2) and TWPs (< 1 mm). ATR yielded well-defined spectra with good signal-to-noise ratios, allowing for a straightforward interpretation of the major functional moieties. Despite reflectance measurements on tyre fragments provided good results, those on TWPs offered limited information due to noise and scattering. Transflectance offered clear peaks and enhanced resolution in the fingerprint region –compared to the other techniques-, much faster analysis times and the ability to effectively measure particles down to 20–10 µm, thus, emerging as the most effective technique for TWPs analysis. However, spectral interpretation is not immediate. Further, a proof-of-concept study was done to evaluate whether the analytical techniques contain information to differentiate types of tyres. An unsupervised pattern recognition and a supervised classification technique (principal components analysis and classification trees, CART) were used, which were able to differentiate among the tyres, notably the truck tyre from the cars tyres. SignificanceThe study presents first time the use of micro transflectance IR to study tyre particles down to 20 µm. Traditional total attenuated reflectance is demonstrated as a suitable way to analyse bigger microplastics. These two options open pathways to monitor this important emerging contaminant in environmental matrices