Household air pollution (HAP) secondary to indoor combustion of solid fuel may be the biggest risk factor for COPD globally, according to a study published on Medscape.

About 3 billion people, half the worldwide population, are exposed to HAP compared with 1 billion people who smoke tobacco.

Interventions that decrease exposure to biomass smoke may decrease the risk for incident COPD and attenuate the longitudinal decline in lung function, the article says.