Indoor Climbing Gyms Exposed to Harmful Shoe Chemicals, Study Finds

Indoor climbing has been an emerging recreation and fitness sport, but one study has revealed that a severe health risk is attached to the sport. Researchers at the University of Vienna and EPFL Lausanne discovered that rubber breakdown at climbing shoe soles releases toxic chemicals into indoor bouldering gyms' atmosphere. Airborne pollutant levels, particularly in highly utilized indoor climbing gyms, may be higher than measured near multi-lane city freeway roadways.

The research, Environmental Science and Technology Air, involved air and dust sampling in various bouldering gyms across Europe, such as Vienna, France, Spain, and Switzerland. Using equipment for particle measurement known as an impinger, which imitates the human respiratory system, scientists found high concentrations of rubber-based chemical additives in the air. The chemicals are from the rubber used in high-performance climbing shoes that is the same chemicals as they are used in car tires.

Among 15 chemicals in 30 sets of climbing shoes tested, chemical 6PPD was predominant. The rubber product stabilizer has been reported to break down into derivatives previously implicated with ecotoxicity in the environment, including aquatic ecosystem fish kills. Although the acute health effects of exposure to the chemicals in climbing gyms are still poorly defined, the detection of these chemicals in high concentrations is a concern.

The study points to a critical need to rethink materials employed in the production of climbing shoes. Most shoe manufacturers utilize rubber compounds with various chemical additives utilized to improve durability and traction without necessarily understanding or recording the environmental and health consequences of their use. Lack of clarity in the industry also makes it harder to bring in safer alternatives.

Results of the research showed that pollution was most severe at peak times at the gym when the majority of climbers were employing the enclosed spaces. Rubber particles, de-stuck from soles, travel into holds and across the gym floor and are constantly disturbed, becoming airborne. Such repeated exposure, the hypothesis of the researchers said, can be particularly harmful to sensitive groups such as children and those with respiratory disease.

Whereas long-term health effects continue under research, analysts suggest that the reaction has to be proactive. Upgraded airflow through the air, increased sanitization of surface areas and hold rooms, and increased off-peak period usage of equipment are among suggested initiatives. Moreover, shifting technology in climber footwear making material with higher emphasis given towards elimination or replacement of detrimental chemical additives with safety considerations provides long-term relief.

The study was aided by gym managers, who said they were eager to make indoor spaces safer. The more that is understood about indoor air quality concerns, particularly in gyms, the more the study can be a driver for change within the industry. Additional interdisciplinary studies are needed to establish the complete extent of the hazards and to inform the development of safer consumer products.

This research serves as a representation of the value of study for daily exposure paths to environmental contaminates, with a particular view to the field of recreation and sport. University of Vienna Environment and Climate Research Hub, where Professor Thilo Hofmann directs alongside colleagues, contributes towards solving such issues in that it is an organization geared towards enhancing unity among scholars addressing global concerns that include climate change, contamination, and extinction of biodiversity.

Source/Credits
Original research in ACS ES&T Air: "The Invisible Footprint of Climbing Shoes: High Exposure to Rubber Additives in Indoor Facilities" by Anya Sherman, Thibault Masset, Lukas Wimmer, Leah K. Maruschka, Lea Ann Dailey, Thorsten Huffer, Florian Breider, Thilo Hofmann
University of Vienna Environment and Climate Research Hub