Tire wear particle and leachate exposures from a pristine and road-worn tire to Hyalella azteca: comparison of chemical content and biological effects

Louise Lynn Halle*, Annemette Palmqvist, Kristoffer Kampmann, Anders Jensen, Tobias Hansen, Farhan Khan

*Corresponding author

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Tire emissions have emerged as an environmental contaminant of concern. To fully understand their effects to biota, research is needed from different stages of a tire’s lifecycle. In this study we exposed freshwater Hyalella azteca to tire wear particles (TWPs) as particle suspensions or their respective chemical leachates (the chemicals released from tire particles into water) from a pristine
(P-TWP) and worn (W-TWP) tire of same make and model. Acute and long-term toxicity experiments on H. azteca showed that P-TWP suspensions were more toxic than W-TWP suspensions with estimated LC50 values of 364 ± 64 particles (0.19 ± 0.03 g L-1) and 3073 ± 211 particles (0.91 ± 0.06 g L-1), respectively. However, leachates from W- and P-TWPs appeared equally toxic, but did not conform to a sigmoidal dose-response pattern and LC50 values could not be derived. In long-term tests (21 d) P-TWP suspensions showed no significant effects on H. azteca mortality (p=0.970) or reproduction (p=0.123), but growth was significantly reduced (p=0.003) at the highest concentration tested (250 particles mL-1 or 0.127 g L-1). Chemical analysis of both particle types and their leachates showed that four compounds, benzothiazole, 1-indanone, aluminium and zinc, consistently leached from TWPs into water. Analysis of the two TWPs showed a difference in the concentration of the various compounds. Specifically, P-TWPs contained significantly more 1-octanethiol, phenanthrene, anthracene and aluminium than W-TWPs, suggesting that they are possible candidates for the increased toxicity observed following P-TWP
exposure.
Original languageEnglish
JournalAquatic Toxicology
ISSN0166-445X
Publication statusAccepted/In press - 26 Jan 2021

Keywords

  • tyre/tire wear; TWP; TRWP; polymer; microplastic

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