structural:reformatting, information:classification
Pollution

Exposure to particulates can bring about the development of COPD, or its exacerbations. Those with COPD are more susceptible to the harmful effects of particulate exposure that can cause acute exacerbations brought about by infections. Black carbon also known as soot, is an air pollutant associated with an increased risk of hospitalization due to the exacerbations caused. Long-term exposure is indicated as an increased rate of mortality in COPD. Studies have shown that people who live in large cities have a higher rate of COPD compared to people who live in rural areas. Areas with poor outdoor air quality, including that from exhaust gas, generally have higher rates of COPD. Urban air pollution significantly effects the developing lung and its maturation, and contributes a potential risk factor for the later development of COPD. The overall effect in relation to smoking is believed to be small.

Poorly ventilated fires used for cooking and heating, are often fueled by coal or biomass such as wood and dry dung, leading to indoor air pollution and are one of the most common causes of COPD in developing countries. Women are affected more as they have a greater exposure. These fuels are used as the main source of energy in 80% of homes in India, China and sub-Saharan Africa.