Panel studies of air pollution in patients with COPD : Systematic review and meta-analysis

•Evidence from panel studies suggests acute effects of PM10 in COPD patients.•An increase in PM10 is associated with an acute decrease of FEV1 in COPD patients.•An increase in PM10 is associated with an acute decrease of PEF in COPD patients.•There is suggestive evidence of an association between PM10 and symptoms.