Scoping of Presence and Impacts of Tyre Wear Particles on Soil Systems

In recent years, concerns over environmental contamination by tyre wear particles (TWPs) have been growing. While previous studies have examined their abundance and ecotoxicological impacts in aquatic environments, research on their abundance in roadside soils—the primary sink of contamination—and their ecological effects on soil properties and terrestrial animals remains limited, calling for further investigation. In this study, Lufa 2.2 test soil and red topsoil sourced from Exeter were dosed with 0.1– 10% TWPs. Spiked soils were analysed for changes in pH, water holding capacity (WHC), and aggregate (stable cluster in soil) formation, as well as for erosion rates using a rainfall simulator. In ecotoxicological assessments, Eisenia fetida, a key species for agricultural production (Jing et al., 2023), were exposed to TWPs and examined their behaviours when contacting to the particles. Then, their bodies were investigated histologically to observe changes in seminal vesicle structures. Concentration of TWP derived elements in earthworm bodies and morphology of ingested TWPs were also examined. Additionally, soil samples were collected from farmland adjacent to highways in three different climatic regions of England to measure environmental TWP concentrations in farmland soil. The amount of TWPs could not be quantified, but TWP derived compounds (styrene, 2-methylbuta-1,3-diene, toluene, and limonene) were detected in every sample. The results of three different investigations above (TWPs’ impacts on soil properties and earthworm health, and concentration in farmland) showed increased soil pH, reduced WHC at higher concentrations, and greater aggregate formation. Earthworms displayed no avoidance behaviour but exhibited a reduction in early-stage sperm cells after short-term exposure, a decrease in growth rate after long-term exposure, and an increase in reproduction, a common response in organisms that are stressed. These findings highlight the potential for TWPs to impair both soil properties and earthworm health, and underscore the need for further work to establish ecological harmful levels.

Author dc:creator

• Kimura, Riko

Contributors dc:contributor

• Richard Thompson, Florence Parker-Jurd

Language dc:language

eng

Repository record dc:identifier

https://pearl.plymouth.ac.uk/bms-theses/482

OAI identifier oai:identifier

oai:pearl.plymouth.ac.uk:bms-theses-1481