A team of researchers from KTH Royal Institute of Technology in Stockholm, Sweden, suggests that replacing the material used in the making of studded winter tires with alternative hard metal could potentially reduce the road wear and the release of airborne particles common with traditional studded winter tires by as much as 20%.

To reach this conclusion, the researchers compared asphalt wear-and-tear and particle emissions incurred by cobalt-based studs with studs made up of an alternative, iron-nickel-based hard metal. The team determined that the iron-nickel stud material was capable of gripping ice and packed snow just as well as the cobalt-based studs, but without causing as much damage to the surface of roads.

How studded tires do damage to pavement and release microparticles. Source: KTH Royal Institute of Technology

"Cobalt is a cheap solution," the researchers explained. "It's so hard that it doesn't wear down, which is why it's also mass produced for rock drilling tools. But asphalt is soft enough that cobalt-containing studs grind and pulverize it into ultra-fine particles that go deep down into the body when inhaled."

Going forward, the team will examine the longevity of alternative stud materials to identify an alternative to cobalt-based studs.

The research is detailed in the article, “A study on the particle emission from cobalt-free studded tires against road materials,” which appears in the journal Tribology International.