Downward transport of naturally-aged light microplastics in natural loamy sand and the implication to the dissemination of antibiotic resistance genes

Transport and transformation of microplastics and nanoplastics in the soil environment: A critical review

“…Yan et al collected MPs from farmland soil in the suburbs of Shenyang, they found that the surface structure of MPs had the photo‐aged phenomenon of local cracking and layered structure formation (Yan et al., 2020). Rod‐shaped plastic fibres (~4 μm) were formed near the highly fibrous MP fragments, indicating that photo‐aged MPs are more fragile to form tiny plastic particles (Yan et al., 2020). The characteristic peak of the carbonyl group at 1711 cm −1 on the FTIR spectrum indicates that the polymer undergoes photooxidation.…”

“…The characteristic peak of the carbonyl group at 1711 cm −1 on the FTIR spectrum indicates that the polymer undergoes photooxidation. The carbonyl index (0.57–0.63) of the aged MPs is much higher than that of the original ones (<0.05), indicating that the photooxidation effect is significant (Yan et al., 2020). Subsequent soil leaching experiment shows that only small rod‐shaped MP fibres (short axis ~15–30 μm) penetrate vertically deep into the soil, which indicates that the photoaging process can promote the transport of MPs by reducing their sizes and reshaping them (Qiu et al., 2020).…”

“…However, the current research on the aggregation behaviour of soil MPs/NPs is conducted in the column filled by porous medium. In addition, the photoaging caused by light exposure in the terrestrial environment also affects the physicochemical properties of MPs/NPs and the release of additives and monomers (Gao et al., 2020; Yan et al., 2020; Zhao et al., 2018). However, our understanding of the transport and transformation of MPs/NPs in the natural soil environment on a longer time scale is relatively limited.…”

Effects of small ridge and furrow mulching degradable film on dry direct seeded rice

“…The use of plastic film ensures the increase and stability of the dry direct-seeded rice yield. However, the extensive use of traditional plastic film has caused serious white pollution, which has affected the ecological environment and food safety [26][27][28] . Incineration is one of the most common ways to deal with traditional plastic film 29 , but the gas generated by incineration pollutes the atmosphere and accelerates climate change 30 .…”

Development and application of tests for microplastic detection in soil

“…This question highlights the need to extend our current knowledge. Scientists have collected evidence of microplastics' hyperaccumulation of other pollutants only for some polymers (polyethylene and polypropylene, see section 1.4) (Ramos et al, 2015;Yan et al, 2020;Yang et al, 2019a;Zhou et al, 2019). Ecotoxicological studies have evaluated mostly polystyrene and light density polyethylene (Cao et al, 2017;Jiang et al, 2020).…”