Hidden dangers in climbing gyms: microplastics from shoes

The air in climbing gyms is more polluted than the air you breathe on the motorway: it's all the fault of the shoes, as demonstrated by a new study

It is widely known that microparticles produced by the wear and tear of car and truck tires on asphalt, which are dispersed into the air, pose health and environmental risks.

However, a lesser-known phenomenon occurs on a smaller scale in indoor climbing gyms, where the source of pollution is not tires but climbing shoes. The soles of these shoes are made from materials similar to those used in car tires, making them potentially hazardous.

A study conducted by researchers from the University of Vienna and the Swiss Federal Institute of Technology Lausanne, published on ChemRxiv, reveals this surprising finding.

The danger of tire microplastics

Research over the past few years has highlighted that, beyond exhaust emissions, there is another significant source of pollution from rubber-tired vehicles.

The wear of tires on roads can generate extremely harmful microplastic particles that accumulate along roadways and enter aquatic ecosystems via rainwater.

These sub-millimeter-sized particles, primarily composed of elastomers, can be inhaled by both animals and humans, leading to severe health and ecological consequences.

In addition to microplastics, tire wear releases trace amounts of chemical additives into the environment. These additives are included in road tires to enhance their performance and durability.

It is estimated that a single tire can contain up to 1,000 additives, many of which have unknown or toxic effects on health and the environment.

One such additive is 6PPD, widely used to protect car tires from ozone. When washed into rainwater, it degrades into 6-PPD quinone, a contaminant linked to mass die-offs of coho salmon in various parts of the world.

The study in climbing gyms

In this new study, researchers collected air and dust samples from two climbing centers and two gyms, finding concentrations of fine dust particles exceeding the safety threshold recommended by the World Health Organization.

The samples revealed 9 and 12 out of the 15 additives investigated, including the hazardous 6PPD.

According to scientists’ estimates, climbers in gyms may inhale more additives than those near a busy road.

It is important to note that this study was conducted on a very small sample size of just four gyms, so more robust data is needed before drawing definitive conclusions.

However, it is crucial to adopt strategies to minimize exposure to these substances in climbing gyms, such as more frequent cleaning, the use of air filters, and, importantly, banning more polluting shoe models.

Source: Chem Rxiv