Fig. 4From: Lung function and systemic inflammation associated with short-term air pollution exposure in chronic obstructive pulmonary disease patients in Beijing, ChinaChanges in IL-2, IL-12 and IFNγ levels in COPD patients with a 1 SD increase in air pollutant levels using the cumulative lag model. Notes: Error bars indicate 95% CIs. *p < 0.05; **p < 0.01Back to article page