Assessment of road run-off and domestic wastewater contribution to microplastic pollution in a densely populated area (Flanders, Belgium)

Maaike Vercauteren; Ilias Semmouri; Emmanuel Van Acker; Emmy Pequeur; Leen Van Esch; Inge Uljee; Jana Asselman; Colin R Janssen

doi:10.1016/j.envpol.2023.122090

Assessment of road run-off and domestic wastewater contribution to microplastic pollution in a densely populated area (Flanders, Belgium)

Environ Pollut. 2023 Sep 15:333:122090. doi: 10.1016/j.envpol.2023.122090. Epub 2023 Jun 21.

Authors

Maaike Vercauteren¹, Ilias Semmouri², Emmanuel Van Acker², Emmy Pequeur², Leen Van Esch³, Inge Uljee³, Jana Asselman⁴, Colin R Janssen⁵

Affiliations

¹ Ghent University, Laboratory of Environmental Toxicology and Aquatic Ecology, Faculty of Bioscience Engineering, 9000, Ghent, Belgium. Electronic address: maaike.vercauteren@ugent.be.
² Ghent University, Laboratory of Environmental Toxicology and Aquatic Ecology, Faculty of Bioscience Engineering, 9000, Ghent, Belgium.
³ Flemish Institute for Technological Research (VITO), 2400, Mol, Belgium.
⁴ Blue Growth Research Lab, Ghent University, Bluebridge, Wetenschapspark 1, 8400, Ostend, Belgium.
⁵ Ghent University, Laboratory of Environmental Toxicology and Aquatic Ecology, Faculty of Bioscience Engineering, 9000, Ghent, Belgium; Blue Growth Research Lab, Ghent University, Bluebridge, Wetenschapspark 1, 8400, Ostend, Belgium.

PMID: 37352959
DOI: 10.1016/j.envpol.2023.122090

Abstract

Plastics are omnipresent in our daily life. Unfortunately, the produced plastics will partly end up in the environment including aquatic ecosystems. People often refer to littering or illegal waste dumping as sources of plastic emission to the environment. However, daily-life sources could also, unknowingly, contribute considerably to the total microplastic pollution in the ecosystem. Hence, there is an urgent need to study these potential sources. In this research, two common sources, i.e. domestic wastewater and road run-off from tire and road wear particles, were studied in detail to quantify the relative contribution of both domestic sources towards microplastic pollution in freshwater ecosystems in Flanders, Belgium. This assessment shows that every person (in studied area) emits on average 1145 microplastics (25-1000 μm) daily through domestic wastewater, resulting in a yearly discharge of 418,000 microplastic particles per person. The road run-off samples contained between 0.02 and 9.2 mg tire wear particles per litre per day, which corresponds to an emission of 10.8 mg tire wear particles per driven vehicle km. The gross and net emissions of both above mentioned microplastic sources were extrapolated to the whole Flanders region using an emission model. From the yearly gross microplastic pollution in the domestic wastewater, 623 kg (20%) will be discharged in the freshwater. The highest losses originated from the households that have a private drain or are not (yet) connected to an active wastewater treatment plant. In Flanders, the yearly net microplastic emission into the aquatic environment of tire wear particles is estimated to be 246 tonnes (38%), mainly from the direct run-off from the road surface. Based on the results, specific mitigation measures can be installed to reduce the emission of microplastics towards the freshwater ecosystem. Other sources should be quantified in a similar way for a more holistic strategy to counteract plastic pollution.

Keywords: Domestic wastewater; Emission to surface water; Fourier-transform infrared spectroscopy; Microplastic pollution; WEISS modelling.

MeSH terms

Belgium
Ecosystem
Environmental Monitoring / methods
Humans
Microplastics*
Plastics
Wastewater
Water Pollutants, Chemical* / analysis

Substances

Microplastics
Plastics
Wastewater
Water Pollutants, Chemical