TY  - JOUR
A1  - Kim, Shin Woong
A1  - Leifheit, Eva F.
A1  - Maaß, Stefanie
A1  - Rillig, Matthias C.
T1  - Time-dependent toxicity of tire particles on soil nematodes
JF  - Frontiers in Environmental Science
N2  - Tire-wear particles (TWPs) are being released into the environment by wearing down during car driving, and are considered an important microplastic pollution source. The chemical additive leaching from these polymer-based materials and its potential effects are likely temporally dynamic, since amounts of potentially toxic compounds can gradually increase with contact time of plastic particles with surrounding media. In the present study, we conducted soil toxicity tests using the soil nematode Caenorhabditis elegans with different soil pre-incubation (30 and 75 days) and exposure (short-term exposure, 2 days; lifetime exposure, 10 days) times. Soil pre-incubation increased toxicity of TWPs, and the effective concentrations after the pre-incubation were much lower than environmentally relevant concentrations. The lifetime of C. elegans was reduced faster in the TWP treatment groups, and the effective concentration for lifetime exposure tests were 100- to 1,000-fold lower than those of short-term exposure tests. Water-extractable metal concentrations (Cr, Cu, Ni, Pb, and Zn) in the TWP-soils showed no correlation with nominal TWP concentrations or pre-incubation times, and the incorporated metals in the TWPs may be not the main reason of toxicity in this study. Our results show that toxic effects of TWPs can be time-dependent, both in terms of the microplastic particles themselves and their interactions in the soil matrix, but also because of susceptibility of target organisms depending on developmental stage. It is vital that future works consider these aspects, since otherwise effects of microplastics and TWPs could be underestimated.
KW  - Caenorhabditis elegans
KW  - exposure time
KW  - lifetime
KW  - microplastics
KW  - soil
KW  - incubation
Y1  - 2021
U6  - https://doi.org/10.3389/fenvs.2021.744668
SN  - 2296-665X
VL  - 9
PB  - Frontiers Media
CY  - Lausanne
ER  -