Fig. 1From: Fine particulate matter aggravates smoking induced lung injury via NLRP3/caspase-1 pathway in COPDCorrelation between clinical outcomes and actual PM2.5 exposure levels in the days preceding the evaluation. (A) SGRQ-C scores. (B) Number of acute exacerbations. The significance is determined by linear regression. * P < 0.05, ** P < 0.01, *** P < 0.001. SGRQ-C, Saint George’s Respiratory Questionnaire for COPDBack to article page