Tyre and road wear particles from source to sea

Abstract

Tyre and road wear particles (TRWP) are an important microplastics contributor to the environment, although direct observations along suggested pathways are virtually absent. There are concerns for both human health and ecosystems from TRWP exposure and leached chemicals. Due to great analytical challenges in detection and characterization, almost nothing is known about the physicochemical characteristics, occurrence, fate and transport of TRWP in the environment. Diverse tyre types exist for different seasons and vehicle profiles, and their formulations are undisclosed proprietary information.Here we show TRWP dispersion in marine sediments, and a direct link between tyre formulation, tread hardness and TRWP emissions. Softer tyres with higher natural rubber and carbon black content generate higher particle wear. Sediment TRWP dominates the microplastics assemblage close to the city, while showing a much more steeply reducing concentration gradient with distance from the source, suggesting different transport behaviour compared to lower density microplastics. This implies that urbanized coastal ecosystems are impacted by the accumulating TRWP, with consequences for sediment ecosystems.One-sentence summaryTyre and road wear particles—The link between tyre formulation, emissions and their spread in the marine environment.

Unraveling the Marine Microplastic Cycle: The First Simultaneous Data Set for Air, Sea Surface Microlayer, and Underlying Water

“…38 Additionally, PE and PP were the most commonly identified polymers in previous microspectroscopy studies in the area, although previously limited to larger size fractions (>50 or >300 μm). 34,35,38,39 Hence, since this study sampled with lower size limits (>10 μm) albeit with lower sampling volumes and the fact that Py-GC/MS and spectroscopy may have different and complementary detection capabilities, the difference in detected polymer clusters is not surprising in general. 41…”

“…The westerly facing zones showed higher concentrations of MP compared to surrounding, urban influenced coasts with less exposure to the North Sea like urban area of Uddevalla . Recent studies already emphasized the occurrence, fate, and transport of MP in these western fjord systems for water, beaches, and sediment samples. − The general presence of MP in this particular environment made it ideal for the presented investigation.…”

“… 34 Recent studies already emphasized the occurrence, fate, and transport of MP in these western fjord systems for water, beaches, and sediment samples. 34 − 39 The general presence of MP in this particular environment made it ideal for the presented investigation.…”

Shades of grey—tire characteristics and road surface influence tire and road wear particle (TRWP) abundance and physicochemical properties

“…The VTI road simulator with the sampling hood mounted on one of the wheels. Photo: Mats Gustafsson, VTI, in (Mattsson et al, 2023).…”

“…Where current velocities decrease, sedimentation may occur quickly, restricting TRWP dispersal through lentic or marine systems. Recently, Mattsson et al (2023) showed TRWP accumulations in sea fjord sediments adjacent to an industrial town, but with a steeply declining concentration gradient, over several km, away from the source.…”