It is already common knowledge that we have contaminated every last corner of the world with microplastics. Less researched is micro-rubber. Empa has made up for this and has come to some unpleasant conclusions: we have released 200,000 tons of microscopically small rubber particles into the environment over the last 30 years. According to study director Bernd Nowack, 97 percent of this is abrasion from car and truck tires, while the rest comes from artificial turf surfaces, for example. Anyone who spends a lot of time on a mountain bike knows that a set of tires is easily worn out every season. During this time, the studs lose a good two millimetres in thickness. Most of the abrasion ends up directly in nature, where the tires are rubbed over the ground.

When asked, Nowack explains that bicycle tires were not taken into account, which he thinks would be interesting in a follow-up study. How big might their share be? The federal government's Mobility and Transport Microcensus can be used as a first approximation. This shows that the Swiss ride an average of 10,000 kilometers by car or motorcycle per year. By bike and on foot (the figures were collected together), the figure is a good 750 kilometers. The truck journeys included in the Empa study are not included in the microcensus and would therefore have to be added to this figure. This shows that new bicycle wear and tear must be modest compared to that of cars, trucks, motorcycles and buses.

However, we are not issuing a warning here, as most mountain bikers are also car drivers. What's more, some bike tours take place between two car journeys that are several times the distance of the bike route. So before we start rationing our mountain bike kilometers, we should question our car driving behavior.
Report SRF website
Report from Radio SRF