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Concept
Plastic pellet pollution
Résumé
Plastic pellet pollution is a type of marine debris originating from the plastic particles that are universally used to manufacture large-scale plastics. In the context of plastic pollution, these pre-production plastic pellets are commonly known as 'nurdles'. These microplastics are created separately from the user plastics they are melted down to form, and pellet loss can occur during both the manufacturing and transport stages. When released into the open environment, they create persistent pollution both in the oceans and on beaches. About 230,000 tonnes of nurdles are thought to be deposited in the oceans each year, where they are often mistaken for food by seabirds, fish and other wildlife. Due to their small size, they are notoriously difficult to clear up from beaches and elsewhere.
Nurdles are the second largest source of microplastics in the ocean. Approximately 27 million tonnes (60 billion pounds) of nurdles are manufactured annually in the United States. One pound of pelletized HDPE contains approximately 25,000 nurdles (approximately 20 mg per nurdle). They are typically under in diameter. Worldwide, about 230,000 tonnes of nurdles are thought to be deposited in the oceans each year.
Plastic resin pellets are classified as primary microplastics, meaning that they were intentionally produced at sizes ranging from 1–5 mm in diameter (whereas secondary microplastics are created through photodegradation and weathering of larger pieces of plastic, like water bottles and fishing nets). Primary microplastics make up between 15% and 31% of the growing amount of marine microplastic pollution, which is related to the corporative expansion of large-scale plastic production. Like microbeads, preproduction plastic pellets can be released directly into the environment as a form of primary microplastic pollution. As more plastic is being produced, more plastic pellets are being deposited in waterways.
A study on a polyethylene production facility in Sweden found that between 3 and 36 million of plastic pellets enter the environment from production sites every year.
Source officielle
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