“…Studies have shown that for each increase in PM 2.5 mass concentration by 10 µg m -3 , all-cause mortality increased by 1.4, 1.5, 2.7, and # These authors contributed equally to this work. 0.8% in Barcelona, Stockholm, Madrid, and the Netherlands, respectively (Mate et al, 2010;Guaita et al, 2011;Ostro et al, 2011;Tobías et al, 2011;Meister et al, 2012), mainly because of the harm from the air pollutants to the cardiovascular and respiratory systems (Chan et al, 2006;Jimenez et al, 2009;Guo et al, 2010;Jimenez et al, 2010;Tsai et al, 2010;Yu et al, 2012).…”