To be clear, the metal in this tire is replacing the pneumatic interior of a traditional tire (air) -- not the rubber tread. It's still a rubber-treaded tire.

To be clear, the metal in this tire is replacing the pneumatic interior of a traditional tire (air) -- not the rubber tread. It's still a rubber-treaded tire. Also, no, there's really no reason to worry about pollution from bicycle tires. It's ~0% of rubber pollution.