Air and dust inside climbing centers contain high levels of rubber particles from the soles of climbing shoes, according to a study that reports that climbers and indoor climbing wall workers are exposed to potentially toxic It is possible that you are inhaling large amounts of rubber additives.
These soles are usually made from the same material as car tires, which are a major source of air pollution. Dust generated by the wear of rubber tires on cars and trucks is inhaled…
Source: www.newscientist.com