Occurrences, impacts, and characterization of microplastics in terrestrial ecosystem to aid policy

The omnipresence of microplastics (MPs) in the environment around the globe has become a great concern to researchers. Increased concentrations associated with MPs and their additives have been discovered in soil, resulting from the application of treated sewerage sludge, plastic mulches to agricultural fields, application of municipal solid waste compost, compost derived from landfill recovered waste, and plastic waste disposal into dumpsites (unlined landfills). The evidence suggested that urban and semi-urban areas in China are highly contaminated with MPs as more studies from China. The lack of stringent policies related to plastic waste disposal is correlated to the elevated MP concentrations in rural areas. Even so, there is a lack of comprehensive knowledge on the environmental fate and transport of terrestrial MPs, particularly the sources, toxicological impacts, and suitable analytical methods for such assessment. Besides, the need of public policy framework to mitigate MP pollution has not been talked through. Therefore, this review focuses on (1) the sources and spatial distribution of MPs in soil; (2) the toxicological impacts of MPs on soil biota and the effectiveness of quantification strategies; and (3) policy recommendations in combating the plastic pollution. Additionally, this study highlights critical future study areas for researchers and decision-makers.