69 / 2021-06-30 14:30:00

Environmental Progress and Effects of Microplastics (MPs) in Soil

Microplastic; Environmental progress; Degradation; Soil

Anthropocentric activities produce over 8.3 billion ton plastics annually, with less than 20% being recycled. Thus, plastics are generally discharged into the environment, and can be degraded into small size. The < 5 mm plastic particles are called microplastics (MPs). Recently, the MPs are widely detected in the environments and are considered as an emerging persistent contaminant. The can cause unpredictable harms to the ecosystem and human health, thus arising the social vigilance. Recently, the focuses and publications of MPs are mainly on the aquatic environment, while they are gradually transferred to the terrestrial system since 2018. We therefore, focus on the environmental progresses in the fate, exposure characteristic, boned-pollutant effects, of, as well as the plastic degradation into MPs in the soils. MPs entering into the soil can migrate and transform rapidly in multi-media, thus making MPs ubiquitous and, ultimately affects humans. Notably, the total amount of plastic discharged into the soil from agricultural emissions has exceeded the discharges into ocean. The major inputs of agricultural sources are mulching film and sludge land use. Many evidences have showed that the organic fertilizer could be also an important source of MPs into the agricultural soil. Plastics degradation in the soil are mainly affected by physicochemical and biological factors, which cause the plastics-polymer fracture, weight losing, surface carbonylation and carboxylation, as well as decomposition into CO₂ and CH₄. Additionally, MPs are easy to absorb organic pollutants due to its large surface area and rich functional groups, which threaten the safety of soil animals, plants and microorganisms. We explore the major environmental progresses of MPs in the soils, in order to shed light on and control the pollution and ecological effects of MPs for the safety of soil ecosystem and human health.