Urumqi, the capital city of Xinjian

Urumqi, the capital city of Xinjiang Uygur Autonomous Region, was carried out to investigate the severe air pollution and the chemistry of heavy haze (Li et al., 2008). The vertical distributions of optical and micro–physical properties of ambient aerosols during haze periods in Shanghai have been revealed recently (Chen et al.,2012). Moreover, population exposures and the corresponding health risks of particulate matter in the ambient air of Yangtze River Delta Region (YRDR) were reported recently (Zhou et al.,2010; Zhao et al., 2011). As inhalable particulate pollutant, PM10 is of primary concern and the potential health risks associated with exposure to PM10 have been evaluated in recent studies (Castro et al., 2011; Xie et al., 2011).