Study demonstrates methodology capable of identifying tire and road wear particles in the environment

In an important step toward improved scientific understanding of tire and road wear particles (TRWP) in the environment, new Tire Industry Project (TIP)-sponsored research has demonstrated the reliable identification of TRWP in complex environmental samples.

Geneva, 23 December 2021: Produced during driving by the friction between tires and road surface, TRWP are a mix of approximately half tire tread material and half road pavement material; they are distinct particles with physical and chemical characteristics that differentiate them from commonly found microplastics.

The study extends the single-particle analysis (SPA) methodology – first described in Kovochich et al., (2021) – from controlled road simulator conditions toward the identification and characterization of individual TRWP in more complex real-world samples, such as road dust, road-dust-spiked artificial sediment, tunnel dust, and environmental settling pond sediment samples.

The particle-differentiation methodology uses existing analytical tools and equipment, which makes it a practical option for laboratories wishing to perform single-particle analysis. Furthermore, the methods address the shortcomings of traditional analytical techniques for microplastics – such as Raman spectroscopy and Fourier-transform infrared spectroscopy (FTIR) – that have proven useful for identifying conventional thermoset plastics but have not been successful for identifying individual TRWP in complex environmental matrices.

To date, the lack of suitable standardized techniques has led to limited observed distributional and abundance data for TRWP in the environment. The peer-reviewed methodology seeks to help fill those data gaps; it will be used in TIP-sponsored research and is available free of charge to improve the accessibility of the method to any scientist engaged in TRWP research.

Identifying and quantifying tire and road wear particles in the environment

TIP has supported research into TRWP for more than a decade, making important contributions to the state-of-knowledge of TRWP characteristics and composition. TIP-sponsored studies have found TRWP are unlikely to negatively impact human health and the environment; however, TIP is engaged in continual research to improve scientific understanding of the potential risks associated with TRWP. To date, TIP has sponsored the following studies relevant to the identification and quantification of TRWP in the environment:

• Characterization of Individual Tire and Road Wear Particles in Environmental Road Dust, Tunnel Dust, and Sediment. Kovochich et al., 2021. Environmental Science & Technology Letters – Link
• Chemical mapping of tire and road wear particles for single particle analysis. Kovochich et al., 2021. Science of the Total Environment – link
• Evaluation of Tire Wear Contribution to PM2.5 in Urban Environments. Panko et al., 2019. Atmosphere – link
• Comparison of Tire and Road Wear Particle Concentrations in Sediment for Watersheds in France, Japan, and the United States by Quantitative Pyrolysis GC/MS Analysis. Unice et al., 2013. Environmental Science and Technology – link 
• Measurement of airborne concentrations of tire and road wear particles in urban and rural areas of France, Japan, and the United States. Panko et al., 2013. Atmospheric Environment – link
• Use of a Deuterated Internal Standard with Pyrolysis-GC/MS Dimeric Marker Analysis to Quantify Tire Tread Particles in the Environment. Unice et al., 2012. International Journal of Environmental Research and Public Health – link
• Comparison of particles generated using different methodologies. (2010) – link 

Discover more about TRWP and TIP-sponsored TRWP research at www.tireparticles.info