Moore, Charles (2002). "A comparison of neustonic plastic and zooplankton abundance in southern California's coastal waters and elsewhere in the North Pacific". Algalita Marine Research Foundation. Archived from the original on 2008-05-16 . Retrieved 2008-02-07.

In 2008, California passed a "nurdle law", which "specifically names pre-production plastic pellets (nurdles) as a pollutant". [35] Recycled plastic pellets, also known as polymer pellets or poly pellets, are made from clean recycled polymers which have been shredded, washed and extruded into uniform shaped pellets ready for use in plastics manufacturing. The animation transitions into the second scene by following the arrows representing the ethylene to the cooler and then to the polymerisation reactor and on to be extruded into strings and pellets, represented by the animated dots. Meanwhile, Karkanorachaki et al. 32 measured the rising velocity of 12 weathered and 12 virgin plastic pellets exposed to the marine environment for 300 days. The rising velocities of virgin and weathered low-density polyethylene, high-density polyethylene and polypropylene pellets varied from 2.25 cm s −1 to 3.22 cm s −1, from 3.11 cm s −1 to 6.25 cm s −1 and from 2.94 cm s −1 to 3.67 cm s −1 respectively. 32 Thus, the rising velocities reported were overall somewhat lower than in the current study and were likely impacted by the presence of holes inserted in the pellets to pass a wire through.

R. W. Obbard, S. Sadri, Y. Q. Wong, A. A. Khitun, I. Baker and R. C. Thompson, Global warming releases microplastic legacy frozen in Arctic Sea ice, Earths Future, 2014, 2, 315–320 CrossRef. The filling material can be used for making decorative pillows as well. What you need to know about using plastic pellets While the biggest, most visible piles of nurdles have been removed, it’s just the tip of the iceberg, says Hemantha Withanage, director and environmentalist at the Centre for Environmental Justice in Sri Lanka.

Theoretical rising velocities Theoretical rising velocities of the pellets were calculated using two methods. The first was the approach of Dietrich 26 as previously applied to calculate theoretical settling/rising velocities for microplastics in water. 27–29 Initially the Equivalent Spherical Diameter ( D n) of the pellets was calculated, defined by Kowalski and co-workers 27 as:P. L. Corcoran, T. Norris, T. Ceccanese, M. J. Walzak, P. A. Helm and C. H. Marvin, Hidden plastics of Lake Ontario, Canada and their potential preservation in the sediment record, Environ. Pollut., 2015, 204, 17–25 CrossRef CAS PubMed. Moore, C; S Moore; M Leecaster; S Weisberg (2001). "A Comparison of Plastic and Plankton in the North Pacific Central Gyre" (PDF). Marine Pollution Bulletin. 42 (12): 1297–1300. doi: 10.1016/S0025-326X(01)00114-X. ISSN 0025-326X. PMID 11827116. A. L. Andrady, The plastic in microplastics: a review, Mar. Pollut. Bull., 2017, 119(1), 12–22 CrossRef CAS PubMed. Waterborne nurdles may either be a raw material of plastic production, or from larger chunks of plastics. [15] A major concentration of plastic may be the Great Pacific garbage patch, a growing collection of marine debris known for its high concentrations of plastic litter.

Freese, Alicia. "Nurdles a big problem in coastal cleanup". Bay Nature. Archived from the original on 2019-02-19 . Retrieved 2019-02-18. A. G. Shard and S. J. Spencer, Intensity calibration for monochromated Al Kα XPS instruments using polyethylene, Surf. Interface Anal., 2019, 51, 618–626 CrossRef CAS. M. Kooi, E. H. Van Nes, M. Scheffer and A. A. Koelmans, Ups and Downs in the Ocean: Effects of Biofouling on Vertical Transport of Microplastics, Environ. Sci. Technol., 2017, 51, 7963–7971 CrossRef CAS PubMed. B. Gewert, M. M. Plassmann and M. Macleod, Pathways for degradation of plastic polymers floating in the marine environment, Environ. Sci.: Process. Impacts, 2015, 17, 1513–1521 CAS.

Plastic pellets are suitable for both crochet and sewing projects

Fig. 4 Relationships between experimental and Waldschläger theoretical rising velocities (top) and between the Corey sphericity factor and Waldschläger theoretical rising velocity as a % of experimental rising velocity.