Microplastic (MP) pollution has raised public concerns in recent decades globally due to its slow degradation and potential toxicity. Most studies have focused on MP contamination in marine, freshwater, and sediment systems. However, much less research attention has been paid to the terrestrial environment, which is a major sink of MPs. In subsurface layers, groundwater is closely related to soils. Nevertheless, research on MPs in groundwater is even less than that in soils. Combining soils and groundwater together, we hypothesize that soil MPs may enter the groundwater system through vertical transport and act as a source of groundwater MP pollution. This review summarizes global occurrences, sources, and pathways of MPs in soils and groundwater. Commonly used analytical methods including sample collection (sites, tools, depth, points, and quantity), sample preparation (drying and sieving), extraction (separation, digestion, etc.), identification (visual sorting, chromatography, and vibration spectroscopy), and quality assurance/quality control are reviewed. Furthermore, the risks and impacts of MPs on soil structures and properties, plants, animals, and antibiotic resistance genes (ARGs) between microorganisms and humans are discussed. Knowledge gaps and future perspectives are also provided.

Occurrences and impacts of microplastics in soils and groundwater

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.