Chemistry:Plastic rain
Plastic rain is the atmospheric deposition of microplastics—particles and fibers less than 5 mm in size—onto the Earth's surface through precipitation (wet deposition) or gravitational settling (dry deposition).[1][2] While microplastics were initially categorized as marine pollutants, subsequent research has identified their presence in the atmosphere, where they can be transported over long distances by wind currents before settling in terrestrial and aquatic environments.[3][4]
Atmospheric transport and deposition
The study of atmospheric microplastics emerged following the standardization of the term "microplastics" in 2004 to describe plastic fragments in marine environments.[5] The potential for atmospheric fallout was documented in 2015, when researchers identified microplastic fibers settling in the urban environment of Paris, France.[3]
In 2019, research extended beyond urban centers to remote locations. A study conducted in the French Pyrenees demonstrated that atmospheric transport mechanisms could carry microplastic particles to high-altitude, uninhabited regions approximately 100 kilometers from the nearest major accumulation sources.[4]
A 2020 study published in Science further characterized the phenomenon by distinguishing between wet deposition, where particles are scavenged by rain or snow, and dry deposition, where particles settle during non-precipitation events. The study estimated that more than 1,000 metric tons of microplastics are deposited annually in protected areas of the western United States, suggesting that the atmosphere facilitates the global transport of plastic particulates.[1]
See also
References
- ↑ 1.0 1.1 Brahney, Janice (2020). "Plastic rain in protected areas of the United States". Science 368 (6496): 1257–1260. doi:10.1126/science.aaz5819. PMID 32527833. Bibcode: 2020Sci...368.1257B. https://doi.org/10.1126/science.aaz5819.
- ↑ Hartmann, Nanna B. (2019). "Are We Speaking the Same Language? Recommendations for a Definition and Categorization Framework for Plastic Debris". Environmental Science & Technology 53 (3): 1039–1047. doi:10.1021/acs.est.8b05297. PMID 30608663. Bibcode: 2019EnST...53.1039H. https://doi.org/10.1021/acs.est.8b05297.
- ↑ 3.0 3.1 Dris, Rachid; Gasperi, Johnny; Rocher, Vincent; Saad, Mohamed; Tassin, Bruno (2015). "Microplastic contamination in an urban area: a case study in Greater Paris". Environmental Chemistry 12 (5): 592–599. doi:10.1071/EN14167. Bibcode: 2015EChem..12..592D. https://doi.org/10.1071/EN14167.
- ↑ 4.0 4.1 Allen, Steve (2019). "Atmospheric transport and deposition of microplastics in a remote mountain catchment". Nature Geoscience 12 (5): 339–344. doi:10.1038/s41561-019-0335-5. Bibcode: 2019NatGe..12..339A. https://doi.org/10.1038/s41561-019-0335-5.
- ↑ Thompson, Richard C. (2004). "Lost at Sea: Where Is All the Plastic?". Science 304 (5672): 838. doi:10.1126/science.1094559. PMID 15131299. https://doi.org/10.1126/science.1094559.
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