Uptake of chemicals from tire wear particles into aquatic organisms - search for biomarkers of exposure in blue mussels (Mytilus edulis)

Little is known about the exposure of aquatic biota to tire and road wear particles (TRWP) washed away from roads. Mussels were exposed for 7 days to model TRWP (m-TRWP), produced by milling tire tread particles with pure sand, and analyzed for 21 tire-related compounds by liquid chromatography-high resolution-mass spectrometry (LC-HRMS). Upon exposure to 0.5 g/L of m-TRWP, 15 compounds were determined from 944 μg/kg wet weight (diphenylguanidine, DPG) over 18 μg/kg for an oxidation product of N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine (6-PPDQ) to 0.6 μg/kg (4-hydroxydiphenyl amine). Transfer into mussels was highest for PTPD, DTPD and 6-PPDQ and orders of magnitude lower for 6-PPD. During 7 days depuration the concentration of all determined chemicals decreased to remaining concentrations between ~50 % (PTPD, DTPD) and 6 % (6-PPD). Suspect and non-target screening found 37 additional transformation products (TPs) of tire additives, many of which did not decrease in concentration during depuration, among them ten likely TPs of DPG, two of 6-PPD and PTPD and two of 1,2-dihydro-2,2,4-trimethylquinoline. A wide variety of chemicals is taken up by mussels upon exposure to m-TRWP and a wide range of TPs is formed, enabling the differentiation of biomarkers of exposure to TRWP and biomarkers of exposure to tire-associated chemicals.

This study was performed in the ANDROMEDA project in the framework of the JPI Oceans Joint Action “Ecological Aspects of Microplastic”. We thank our cooperation partners in this project for fruitful discussion and collaboration. We gratefully acknowledge funding by the German Ministry for Education and Research (BMBF; FKz 03F0850A). The authors wish to thank the ProVIS Centre for Chemical Microscopy which is supported by European Regional Development Funds (EFRE) and the Helmholtz Association for providing access to the scanning electron microscope. Technical support by Petra Keil (UFZ) is gratefully acknowledged. We also want to thank the laboratory technicians of the ILVO Marine Analytical Lab and Aquaculture lab for technical support during the exposure experiment.

Peer reviewed