Table 1.

Sources of microplastics and nanoplastics into the environment.

MNPs’ source	Properties	Entry point into the environment	Application	References
Plastic pellets	Granular plastics, commonly with a diameter of 2–5 mm and a regular shape	Drifting/surface runoff/loss	Raw materials and building blocks for nearly every plastic product.	Karkanorachaki et al. (2018); Mendoza et al. (2018)
Microbead personal care products	Microbeads varying in color and ~ 100–1,000 μm	Wastewater/sewage sludge	Exfoliating, film-forming, hydrophilic, scrubbing agents and functionalized polymers in personal care products as well as in biomedical applications.	Napper et al. (2015); Nel et al. (2019)
Paint	Between 0.3 and 5 mm from synthetic polymers mainly alkyds, epoxy resins, poly(acrylate/styrene) and polyurethane	Surface runoff	Architectural coatings, marine coatings, automotive coatings, and road-marking paint.	An et al. (2020); Gaylarde et al. (2021)
Textile fabric	100–1,000 μm MNPs mainly from acrylic, polyethylene terephthalate, and nylon fabrics	Wastewater/sewage sludge	Enhanced appeal and functionality in synthetic fabrics.	Carney Almroth et al. (2018); Cai et al. (2020b)
Sewage treatment effluents	Different kinds of MNPs from automobile tire wear, industrial production of plastic, personal care products, chemical laundry products, urban debris, etc. Ranging from 0.1 μm to 5 mm	N/A	N/A	Domogalla-Urbansky et al. (2019); Mak et al. (2020)
Sports ground (artificial turfs and running tracks)	MNPs from propylene, polyamide 6 (PA6), PE, or polyurethane, styrene-butadiene rubber, thermoplastic elastomer, and green rubber and ethylene propylene diene monomer which is made of EPDM. Usually between 0.5–2.5 mm	Drifting/surface runoff	N/A	Wang et al. (2019); van Kleunen et al. (2020)
Vehicle tire wear	Roundish, kidney-shaped or elongated particles from styrene butadiene rubber and natural rubber particles 0.01–350 μm	Surface runoff	N/A	Sommer et al. (2018); Järlskog et al. (2020)
Municipal debris	Fragments of plastic bags, plastic bottles and other packaging materials. Of varying particle sizes from 0.1 μm to 5 mm	Drifting/surface runoff	N/A	Welle and Franz (2018); Sobhani et al. (2020)
Fishing gears	Polyethylene, polyamide (nylon), and polypropylene monofilaments of between 0.1 and 5 mm	Drifting/loss	N/A	Dowarah and Devipriya (2019); Xue et al. (2020)
Farming films	Microfilms more commonly from polyethylene between 0.03 and 10 mm	Drifting/surface runoff	N/A	Liu et al. (2018); Zhang and Liu (2018)
Construction industry	Fragments of typically polyamide, polyethylene, polyvinylchloride and polyurethane polymers	Drifting/surface runoff	N/A	Dehghani et al. (2017); Xu et al. (2020)

N/A—Not applicable.