Fate and impact of nano/microplastic in the geoenvironment — ecotoxicological perspective

Plastic pollution in the terrestrial environment is emerging as another significant human-made threat to ecosystem function and health. Plastic contamination can range from the macro- to the nanoscale, and environmental impacts are evident at each level. Although significant knowledge gaps remain regarding the interactions between the natural environment and nano- and microplastics (NMPs), there is an increasing body of evidence concerning detrimental effects on a wide range of taxa. The surface properties of NMPs lead to the adsorption of heavy metals, endocrine-disrupting chemicals, antibiotics and other persistent organic pollutants, which, therefore, can result in their co-migration in the terrestrial environment. Although airborne and dietary transmission routes of NMPs have been observed, their effects on human health are still not fully understood, which is of concern to the scientific community. This state-of-the-art review paper firstly examines available evidence for, and knowledge of, various sources of NMP contamination to the terrestrial environment. Attention then focuses on (a) the biological processes from the source to soils and plants, (b) potential impacts of NMPs on soil and subsurface ecosystems, (c) trophic interactions and function and (d) implications for environmental and human health. This paper concludes by identifying knowledge gaps and presents recommendations on prioritised research needs.