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Nurdles and Tire Dust

Susan Eastwood

November 2022

How much do you know about microplastics?


We all know that microplastics are a growing source of pollution in the oceans, causing harm to marine life and working its way up the food chain to impact human health. Eight hundred marine species are affected by marine microplastics, including all types of sea turtles.


But you may not be familiar with the top two sources of ocean micropollutants: NURDLES and TIRE DUST! These are both “primary microplastics,” already  tiny when they enter the waterways as a pollutant, as opposed to “macroplastics,” which include single-use bags and fishing gear that can cause harm by entangling wildlife or by breaking down into microplastics once in the sea. 


The NUMBER ONE source of ocean micropollutants? Small particles from our vehicle tires! Tire wear microplastic particles (TWP) abrade from vehicle tires as they roll along the roads, creating microplastics of synthetic rubber, often known as tire dust. 6.1 million tons are deposited into our air and water each year, and are found in even remote corners of the world. U.S. tires contribute about  1.8 million tons annually. These particles can be so small that they are carried in the air and may be inhaled, contributing to air pollution and respiratory issues. Rain washes the dust off the roads, and it ends up in our waterways and eventually in the ocean. TWP is recognized to be the largest source of microplastics in the ocean, as much as 28%.


Tires are made primarily from synthetic rubber, produced from crude oil. There are no regulations on tire wear or the thousands of chemicals they contain, some of which are carcinogens, and may include zinc, lead, and chlorine. Massive die-offs of Coho salmon have been linked to the chemical 6PPD-quinone, from tire dust. This chemical is toxic to marine life, and has been shown to damage human DNA in lab tests. And if that isn’t bad enough, recent studies point out that tire dust has a greater impact on air than modern car emissions, producing up to 2000 times as many particulates!

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Photo: Tire on pavement; Image by Mikes-Photography

Fortunately, there are companies working on solutions, including devices to capture the tire dust and sustainable ways to produce synthetic rubber from natural sources instead of fossil fuels. Others are calling for regulations and bans of toxic chemicals in tires. 


You may be wondering “What about the rest of the tire when it wears out?” Well, they are considered hazardous waste, at least until they are “recycled” into children’s playgrounds, but that is a story for another day.

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Photo: Tires stacked; Image by Pexels from Pixabay

NURDLES are the  second largest source of ocean micropollutants. Nurdles are tiny polyethylene pellets, which resemble lentils, or fish eggs (which makes them an attractive dinner to fish). They are easily transported this way to be made into thousands of plastic products, but despite industry promises, over 230,000 tons end up in the ocean every year, due to accidents, spills or simply being carried off by the wind. Next time you are at the shore, see if you find any of these tiny plastic pellets washed up.

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Photo: Close up of nurdles on the beach sand; Image by Hillary Daniels on Flickr

Photo: Lots of nurdles among trash found along the coast; Image by hockadilly

Nurdles are made when fracked gas is “cracked” to make polyethylene in “cracker plants,” which are often located in environmental justice communities. As renewable energy lessens the demand for fossil fuels as gas and heating oil, the big oil companies are ramping up plastic production to keep their businesses profitable. They plan for plastics to be fifty percent of oil demand by 2050. Needless to say, they are NOT planning to reduce fossil fuel production, making it impossible to meet our crucial climate goals to avert climate disaster. Read a great case study in the latest Sierra magazine.

Both of these top sources of ocean pollution come from fossil fuels! So do the other two top sources of ocean microplastics, textile fibers and personal product ingredients. Also plastics!

It is important for us to recognize the connections between our Sierra Club work on renewable and energy efficiency and the campaigns for Zero Waste and reducing plastics, especially single use plastics.

Making these connections allows us to point with certainty to the real source of ocean micropollutants (and much more); it is the fossil fuel industry!



Sierra: These Are the New Titans of Plastic 

National Geographic: Tires: The plastic polluter you never thought about

The Guardian: Car tyres produce vastly more particle pollution than exhausts, tests show 

Green Matters: Car Tire Dust Is a Major Source of Microplastics, and It’s Killing Marine Life 

Susan Eastwood is Chapter Chair of Sierra Club Connecticut.

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