Indoor Climbing Wall Users May Be Breathing Toxic Rubber Dust Linked to CANCER

Indoor climbers could be at risk of cancer and other diseases.

A study has found that the air at popular indoor rock climbing wall facilities is laden with potentially toxic rubber particles.

Scientists took air samples at two climbing gyms, as well as dust samples from those and two other facilities.

The concentrations of some of the rubber particles found swirling in the air exceeded those of several megacities around the world.

The team of scientists found nine of the 15 debris particles they analyzed in air samples and 12 of the 15 in dust samples.

Not all substances are carcinogenic; most of them can cause headache, dizziness, irritation of the respiratory system and skin irritation.

But one of the chemicals detected, benzothiazole, has been linked to an increased risk of bladder cancer among factory workers.

Rubber is a key component of any good climbing shoe. It provides the shoes with optimal friction at climbing points and provides the wearer with flexibility and the right amount of rigidity to grip where needed and maintain its shape.

But with each climb and each foothold, particles of rubber from the shoes (the same type used to make car tires) are released into the air and into the footholds themselves.

Many climbers have hold brushes, which makes the situation worse because pollutants are constantly raised into the air, which people inhale and then swallow.

Researchers from the University of Vienna took samples of the air, the soles of climbing shoes, the dust left on the footholds and the dust deposited around the facilities.

Airborne particle concentrations exceeded World Health Organization guidelines by approximately 20 times.

WHO guidelines for indoor particulate matter concentrations are set at 45 micrograms per cubic meter (μg/m3) over a 24-hour period. In the climbing rooms the researchers visited, concentrations of respirable particles ranged between 900 µg/m3 and 1,040 µg/m3.

They said: ‘[Chemical classes] PPD and PPDq concentrations in the respirable fraction were higher than those measured in Chinese megacities and similar to those at roadside sites and city centers in China during air pollution events.

‘Concentrations of [chemicals] DPG, BTZ and 2OH-BTZ aerosol [particulate matter] The samples were one or two orders of magnitude higher than those from 18 megacities around the world and the concentrations of BTZ and 2OH-BTZ were up to 10 times higher than those in industrial areas in Spain.

Most of the rubber particles detected are known to cause irritation to the respiratory tract and skin. Some of them are known to be toxic to fishwhile benzothiazole (BTZ) is a carcinogenic agent in rodents.

After checking the concentrations of the 15 different chemicals in air samples, where they detected nine, and dust samples, where they detected 12, they investigated climbing shoes and the footholds they cling to.

They sampled 30 different shoe soles from a variety of brands and found one or more chemicals in all of them. One shoe showed evidence of all 15 chemicals.

Overall, chemical concentrations in the shoes averaged 711 micrograms per gram of sole material.

The researchers said: “With increasing global urbanization, we expect to live, work and recreate in safe indoor environments.” Especially in indoor sports facilities, where breathing increases, air quality standards must be high and safe.

‘Rubber formulations containing potentially toxic substances. [rubber-derived chemicals] It should not be used in climbing shoes or other consumer products where high human exposure is likely to occur.

The team’s work, published in a prepress serverhas not yet undergone the peer review process, so its findings can be taken with some caution for now.

At the same time, it is well documented that rubber additives used to make tires, some of which are also used in climbing shoes, spill off the road and leak into the environment.

Tests by Emissions Analytics, a UK-based engineering consulting firm, reported last year that tires produce about 2,000 times more mass particle pollution than exhaust pipes.