Tire wear particle emissions: Measurement data where are you?

David Mennekes; Bernd Nowack

doi:10.1016/j.scitotenv.2022.154655

Tire wear particle emissions: Measurement data where are you?

Sci Total Environ. 2022 Jul 15:830:154655. doi: 10.1016/j.scitotenv.2022.154655. Epub 2022 Mar 18.

Authors

David Mennekes¹, Bernd Nowack²

Affiliations

¹ Empa - Swiss Federal Laboratories for Materials Science and Technology, Technology and Society Laboratory, Lerchenfeldstrasse 5, CH-9014 St. Gallen, Switzerland.
² Empa - Swiss Federal Laboratories for Materials Science and Technology, Technology and Society Laboratory, Lerchenfeldstrasse 5, CH-9014 St. Gallen, Switzerland. Electronic address: nowack@empa.ch.

PMID: 35314235
DOI: 10.1016/j.scitotenv.2022.154655

Abstract

Tire wear particle (TWP) emissions are gaining more attention since they are considered to contribute a major share to the overall microplastic emissions and are suspected to be harmful to flora, fauna and humans. Hence, recent studies derived country-based TWP emissions to better understand the significance of the problem using either tire emission factors (EF) or a material flow analysis (MFA) of tires. However, all 14 country-based TWP emission studies found and published since the year 2000 base their calculation on other studies rather than own measurements. Therefore, we started to search for the actual TWP measurements which the 14 studies would rely on. As a result, we found a network of 63 studies which were used to derive TWP emissions in different countries and regions. Only in few cases (12%) TWP emission studies reference directly to a measurement study to derive TWP emissions, but mostly (63%) they rely on reviews or summarizing studies. Additionally, we could not obtain 25 studies in the analysed network. In total we found nine studies which actually measured TWP emissions. Out of these four studies originate from the 1970s, one analysed only light vehicles and one only considered buses. Thus, only three non peer-reviewed studies were considered to show trustful results which were cited a maximum of three times in the network. The obtained 14 country-based studies suggest TWP emissions of about 1.3 kg capita^-1 year^-1 for the EF approach and 2.0 kg capita^-1 year^-1 for the MFA approach (overall range: 0.9-2.5 kg capita^-1 year^-1). Consequently, we call for an urgent need to minimize uncertainties of TWP emission estimates to better understand the contribution of TWP to the overall microplastic pollution of the environment. A better understanding about quantities could also help to better address the risk of environmental pollution by TWP.

Keywords: Country-based tire wear particle emission; Emission factor; Material flow analysis; Vehicle tire emission.

MeSH terms

Air Pollutants*
Environmental Monitoring
Humans
Microplastics*
Motor Vehicles
Plastics
Vehicle Emissions / analysis

Substances

Air Pollutants
Microplastics
Plastics
Vehicle Emissions