Air pollution
Although smoking is thought to be the greatest risk factor for developing COPD, an estimated 25–45% of patients with COPD have never smoked.1 Exposure to indoor and (to a lesser extent) outdoor air pollution plays a major role in the development of COPD for some individuals.2
A particularly strong association exists between the development of COPD and the use of biomass fuel for cooking and heating.1 Biomass fuel (including wood, charcoal and animal dung) releases a large amount of particulate matter into the air and, when combined with poorly ventilated dwellings and living conditions, there is a large risk of developing respiratory disorders.1 Reduction to exposure to smoke from biomass fuel is an important aim to reduce the prevalence of COPD worldwide.2
Frequent use of mosquito coils is also a risk factor for COPD, since burning a mosquito coil for 8 hours releases the same amount of particulate matter as smoking 4 to 6 packs of cigarettes.3
Outdoor air pollution from motor vehicle emissions and combustion of other fossil fuels may also play a role in the development of respiratory problems, although the link to COPD remains unclear and the effects are smaller than compared with smoking.2
References
1. Salvi SS, Barnes PJ. COPD in non-smokers. Lancet 2009;374;733-743.
2. Global Initiative for Chronic Obstructive Lung Disease. Global strategy for the diagnosis, management, and prevention of COPD. 2011. www.goldcopd.org
3. Liu W, et al. Mosquito coil emissions and health implications. Environ Health Perspect 2003;111;1454-1460.