Macro- and microplastic accumulation in soil after 32 years of plastic film mulching

Breakdown and Modification of Microplastic Beads by Aeolian Abrasion

“…The experiments reported here used spherical, compact microbeads. Microbeads can be present in soils as a result of treatments such as the application of biosolids for fertilization , but are not as common as films derived from plastic film mulching or fibers from long distance atmospheric fallout. ,, For mineral particles, processes of entrainment, transport, and interaction are known to vary with particle shape, and because the same will be true for microplastic particles, the abrasion processes reported here are only expected to be directly relevant to compact microplastics. Microplastic fibers and fragments can exhibit weathering and wear patterns similar to those reported here, including the attachment of small mineral particles to the polymer surface, and further controlled experiments are required to determine how rapidly such features develop on microplastics of different shapes during aeolian abrasion.…”

“…The experiments reported here used spherical, compact microbeads. Microbeads can be present in soils as a result of treatments such as the application of biosolids for fertilization 7 , 14 but are not as common as films derived from plastic film mulching or fibers from long distance atmospheric fallout. 6 , 53 , 54 For mineral particles, processes of entrainment, transport, and interaction are known to vary with particle shape, and because the same will be true for microplastic particles, the abrasion processes reported here are only expected to be directly relevant to compact microplastics.…”

“…Wind erosion redistributes over 6 billion tons of soil annually and is increasing in some environmentally sensitive regions . In addition to the transport of minerogenic particles, wind erosion of soils can also redistribute organic, industrial, and agricultural materials where they are present at the soil surface. − One material found in soils and susceptible to wind erosion is plastic which has potentially serious consequences for human health, global biogeochemical cycling, and ecosystem functioning. , Plastics have been identified in soils worldwide and can be present as both macroplastics (≥5 mm in size) and microplastics (<5 mm in size) . Although the low density, high strength to weight ratio, and large surface area of some macroplasticssuch as bags and balloonsmean that they can be blown considerable distances, the main research focus for wind erosion and atmospheric transport is microplastic entrainment and dispersal. , Microplastics are solid synthetic-polymer-containing particles and may be purposefully produced to be small in size (primary microplastics) or derived from the breakdown of macroplastics (to form secondary microplastics) by chemical, microbial, and/or mechanical processes. , Microplastics may be present in soils due to the environmental breakdown of plastic mulching material used in agriculture or the application of waste water or sewage fertilizer containing microplastics , but have also been identified in remote or upland soils with no history of agricultural use , where their presence is attributed to atmospheric deposition following long distance transport by wind. , …”

“… 5 , 6 Plastics have been identified in soils worldwide and can be present as both macroplastics (≥5 mm in size) and microplastics (<5 mm in size). 7 Although the low density, high strength to weight ratio, and large surface area of some macroplastics—such as bags and balloons—mean that they can be blown considerable distances, 8 the main research focus for wind erosion and atmospheric transport is microplastic entrainment and dispersal. 5 , 9 Microplastics are solid synthetic-polymer-containing particles and may be purposefully produced to be small in size (primary microplastics) or derived from the breakdown of macroplastics (to form secondary microplastics) by chemical, 10 microbial, 11 and/or mechanical processes.…”

Effect of Dry Soil Aggregate Size on Microplastic Distribution and Its Implications for Microplastic Emissions Induced by Wind Erosion

“…Most plastic film materials used for farmland soils are low-density plastic materials. , In addition, the MP polymers in northern Chinese farmlands primarily consist of low-density components such as low-density polyethylene, polypropylene, and polyester. , The low-density MPs were extracted from the surface soil and wind-blown sand and dust samples using the density separation method with a saturated sodium chloride (1.19 g cm –3 ) solution (Text S1). MPs were collected on a filter film and transferred to glass Petri dishes.…”