Polyethylene microplastics influence the transport of organic contaminants in soil

Thorsten Hüffer; Florian Metzelder; Gabriel Sigmund; Sophie Slawek; Torsten C Schmidt; Thilo Hofmann

doi:10.1016/j.scitotenv.2018.12.047

Polyethylene microplastics influence the transport of organic contaminants in soil

Sci Total Environ. 2019 Mar 20:657:242-247. doi: 10.1016/j.scitotenv.2018.12.047. Epub 2018 Dec 5.

Authors

Thorsten Hüffer¹, Florian Metzelder², Gabriel Sigmund³, Sophie Slawek⁴, Torsten C Schmidt⁵, Thilo Hofmann⁶

Affiliations

¹ University of Vienna, Department of Environmental Geosciences and Environmental Science Research Network, Althanstrasse 14, 1090 Vienna, Austria; University of Vienna, Research Platform Plastics in the Environment and Society (PLENTY), Althanstrasse 14, 1090 Vienna, Austria.
² University of Duisburg-Essen, Instrumental Analytical Chemistry, Universitätsstrasse 5, 45141 Essen, Germany; Deutsches Textilforschungszentrum Nord-West GmbH, Adlerstraße 1, 47798 Krefeld, Germany.
³ University of Vienna, Department of Environmental Geosciences and Environmental Science Research Network, Althanstrasse 14, 1090 Vienna, Austria; Institute for Hydrochemistry, Technical University Munich, Marchioninistrasse 17, 81377 Munich, Germany.
⁴ University of Vienna, Department of Environmental Geosciences and Environmental Science Research Network, Althanstrasse 14, 1090 Vienna, Austria.
⁵ University of Duisburg-Essen, Instrumental Analytical Chemistry, Universitätsstrasse 5, 45141 Essen, Germany; Centre for Water and Environmental Research (ZWU), University of Duisburg-Essen, Universitätsstrasse 2, 45141 Essen, Germany; IWW Water Centre, Moritzstrasse 26, 45476 Mülheim an der Ruhr, Germany.
⁶ University of Vienna, Department of Environmental Geosciences and Environmental Science Research Network, Althanstrasse 14, 1090 Vienna, Austria; University of Vienna, Research Platform Plastics in the Environment and Society (PLENTY), Althanstrasse 14, 1090 Vienna, Austria. Electronic address: thilo.hofmann@univie.ac.at.

PMID: 30543972
DOI: 10.1016/j.scitotenv.2018.12.047

Abstract

Plastics are now found in all natural environments including soil. The effects of microplastics in terrestrial systems, however, remain largely unexplored. Polyethylene is one of the mass-manufactured polymers found in terrestrial environments. It is used in many different sectors, for example in agricultural mulches, composite materials, and packaging. The presence of microplastics in soil, including polyethylene, can affect the transport of hydrophobic organic pollutants including pesticides. The objective of this study was to investigate the influence of polyethylene microplastics (<250 μm) on the transport of two selected organic plant-protection agents (atrazine and 4-(2,4-dichlorophenoxy) butyric acid) in soil under different aqueous conditions, using inverse liquid chromatography. The distribution coefficients for the sorbates that were sorbed to pure polyethylene microplastic were found to be significantly smaller than those for the sorbates sorbed to pure soil. The addition of 10% (w/w) polyethylene to the soil therefore led to an overall reduction in sorption, but the sorption trends due to variations in pH and ionic strength were not affected. The results imply that the presence of polyethylene microplastics in soil may therefore increase the mobility of organic contaminants by reducing the sorption capacity of natural soils, which must be validated by further research.

Keywords: Environment; Fate; Inverse chromatography; Mobility; Polymers; Sorption.