Microplastics Such as Tire Dust Are Found to Pollute the Oceans

Everyone knows that plastics are a major cause of pollution in our seas today. However, not everyone is aware that they have extremely small versions that are present in all bodies of water. What's more surprising is that they come from one unassuming material: tire dust.

"These urban stormwater findings really surprised us," said Rebecca Sutton, main author of the study and senior scientist for the research center San Francisco Estuary Institute and Aquatic Science Center (SFEI).  "We were not anticipating such high levels."

Classified as microplastics, SFEI defines them as "plastic particles smaller than 5 millimeters, are the remnants of bottles, cigarettes, clothing fibers and a seemingly endless list of plastic products. They're pushed by rain into storm drains and carried through rivers and creeks into the bay."

What's more, half of the plastic products found came from field samples that were black fragments with a "distinctive rubbery texture when handled with tweezers."  These "fragments" are tire dust.

But isn't tires made from--well--rubber? So how come there's plastic in it?

While it's true that tires are made from synthetic and natural rubber, they also contain plasticizers, dyes, and flame retardants. These fragments get washed off on the roads when a tire wears off, eventually finding themselves in bodies of water. This exposes organisms to health risks that vary depending on their species, type, shape, and dose concentration once they ingest these chemicals. It can affect the entire food chain itself.

It's a growing threat to the aquatic ecosystem--including fishes, shellfish, and the entire marine environment. Unfortunately, it's highly persistent and hard to get rid of. SFEI reports that these substances are "very resistant to environmental (bio) degradation and will remain stable in the environment long after their release."

This should alert tire makers to find other ways to make their products more "earth-friendly."  Otherwise, the word "sushi" might someday cease to exist in our vocabulary.