By now it should be pretty clear to see that wherever rock climbers go, chalk follows. In many instances this has proven to have detrimental effects, such as inhibiting vegetation growth and causing visual damage to natural spaces. While the previous posts in this blog series have focused on the environmental pollution caused by chalk in outdoor environments, the next few posts shall centre on its use and impacts in indoor spaces.
Climbing chalk contributes to indoor air pollution
When chalking up for a climb, climbers create plumes of chalk dust that cause the release of dust particles into the air. In outdoor environments, this isn’t that big of a deal as the dust particles can easily dissipate in the open. However in indoor climbing gyms, these dust particles become trapped within the confined space and circulate around. As they increase in concentration along with the number of climbers present in the gym, the air could even start to appear slightly hazy.
A study of rock climbing gyms in Germany found that indoor rock climbing gyms have high concentrations of PM2.5 and PM10 particles. Hydrated magnesium carbonate hydroxide found in chalk was determined to be a particle source contributing to indoor air pollution. According to the study, the average off-peak hour concentrations of PM10 ranged 200-500 μg m−3 while the concentration for PM2.5 measured between 30-100 μg m−3. During peak hours, concentrations could shoot up to 4000 μg m−3 and 500 μg m−3 for PM10 and PM2.5 respectively (Weinbruch et al., 2008). In a similar study conducted by the University of Colorado Boulder, the maximum 6-hour average concentration of PM10 was recorded at 190 μg m−3 (Almand-Hunter et al., 2014).
Effects on indoor air quality
Singapore does not have any official regulations governing Indoor Air Quality (IAQ), and to the best of my knowledge, there are no pollutant standards for IAQ in Singapore. Hence, I will be using NEA’s Pollutant Standards Index (PSI) as a benchmark.
Comparing the results of the climbing gym studies to NEA’s breakpoints in the computation of PSI, the concentrations of PM2.5 falls between the Moderate to Unhealthy range while the levels of PM10 range from Unhealthy to Hazardous. At these levels, health effects can be expected for most of the population while sensitive groups may face more serious effects.
The studies revealed a wide range of fine particulate matter concentrations in climbing gyms. These results could perhaps be explained by the different sizes of the gyms that were surveyed and the varying efficiency of their indoor ventilation systems. While this may not be a fully accurate point of comparison, I do believe that this still presents an objective estimate of the serious effects chalk usage can have on IAQ.
References
Almand-Hunter, B. B., Gordon, J., Masson, N., Hannigan, M. P., & Miller, S. L. (2014). Dust exposure in indoor climbing facilities. Indoor Air, 233-9.
NEA. (n.d.). Computation of the Pollutant Standards Index (PSI). Retrieved from https://www.nea.gov.sg/our-services/pollution-control/air-pollution/faqs
Weinbruch, S., Dirsch, T., Ebert, M., Hofmann, H., & Kandler, K. (2008). Dust exposure in indoor climbing halls. Journal of Environmental Monitoring, 10(5), 648-654.
