A surprisingly compelling subject
Dinner table, or social media, conversation may centre on arguments over which football team deserves to win the league, or whether the Mustang or Camaro is better, but the common feature of such polemics is that they represent simple and interesting questions. The topic of tyres, however, and if you dare raise it, may stun your companions into silence. Tyres are not simple and interesting. They are complex and boring – at least on the outside.

Emissions testing is usually preoccupied by testing for known, worrisome chemicals in the environment. Often they are in small amounts or concentrated at hotspots.  Sophisticated equipment is deployed to find and measure them.  We obsess with ever-tighter regulation of these pollutants we know about, even well beyond the point of diminishing environmental returns.

Reusing, recycling, repairing and sharing are defining hallmarks of a circular economy idea that is being promoted worldwide, but especially in Europe. 

We know, from earlier research, that tyres emit lots of particles, both coarser and the more potentially dangerous ultrafines. To put this in context, the levels are less than from exhausts of many older diesel vehicles without filters, but orders of magnitude greater than from the exhausts of modern internal combustion engine vehicles with the latest filters. But, where do these particles go, and can they be found in the environment?

Not since the Chevrolet Corvette Stingray or perhaps, more recently, the Citroen Nemo, have cars and fish been so closely associated.  But this time it is not branding, but rather the pollution of one by the other.