At a Glance
- A study found that indoor climbing gyms contain rubber-derived compounds from climbing shoes, raising concerns about air quality and potential health effects for gym users.
- Researchers tested air and dust samples in gyms across Europe and found chemical concentrations comparable to those on busy roads, especially in high-traffic facilities.
- One key compound identified was 6PPD, a tire additive linked to environmental damage. Its implications for human health in enclosed spaces are unclear but concerning.
- The study highlights the need for better gym ventilation, cleaning practices, and safer materials in climbing shoe manufacturing to reduce indoor air pollution.
- Scientists urge further investigation into the health risks of these airborne compounds and advocate for cleaner indoor climbing environments to protect all users, especially vulnerable groups.
A new study published in ACS ES&T Air reveals that the air in indoor climbing gyms may contain harmful chemicals from the soles of climbing shoes. Researchers from the University of Vienna and EPFL Lausanne found high concentrations of rubber-derived compounds (RDCs) in the air, similar to those found in car tires. These chemicals can be released during the abrasion of climbing shoes as climbers move across the gym’s surfaces. The study suggests that exposure to these chemicals might be a health concern for climbers.
The research team, led by environmental scientist Anya Sherman, tested the air in multiple bouldering gyms in Vienna, France, Spain, and Switzerland. They collected air and dust samples using a device that mimics the human respiratory tract. The results showed that the concentration of these harmful compounds in the gym air was higher than expected and comparable to pollution levels on busy city roads. The team found that the levels of chemicals were especially high in gyms with many climbers, suggesting that the more activity, the more chemicals are released into the air.
Among the chemicals detected was 6PPD, a rubber stabilizer commonly used in tire manufacturing. This compound has been linked to environmental harm, including the deaths of salmon in rivers. While the exact impact of these chemicals on human health remains unclear, the study’s authors stress that these substances should not be in the air we breathe, especially in enclosed spaces like climbing gyms. The team emphasized that more research is needed to understand the potential health risks, particularly for vulnerable groups such as children.
The researchers are calling for action to improve the air quality in climbing gyms, such as better ventilation, cleaning protocols, and using climbing shoes made with fewer harmful chemicals. They also hope their findings will inspire manufacturers to rethink the materials used in climbing shoe soles. The study underscores the importance of making climbing environments safer for everyone while continuing to enjoy the sport.
References
- University of Vienna. (2025, April 29). Chemicals released by climbing shoe abrasion could lead to lung issues for climbers in indoor environments. Phys.Org; University of Vienna. https://phys.org/news/2025-04-chemicals-climbing-abrasion-lung-issues.html
- Sherman, A., Masset, T., Wimmer, L., Maruschka, L. K., Dailey, L. A., Hüffer, T., Breider, F., & Hofmann, T. (2025). The invisible footprint of climbing shoes: High exposure to rubber additives in indoor facilities. ACS ES&T Air, acsestair.5c00017. https://doi.org/10.1021/acsestair.5c00017
