Size characteristics and health risks of inorganic species in PM1.1 and PM2.0 of Shanghai, China, in spring, 2017.

Ambient particulates of Shanghai with 5-stage particle sizes were firstly determined in spring, 2017. The particles' mass concentrations were mainly observed in fine particle matter (PM1.1) and coarse particles (diameter > 7.0 μm). Water-soluble ionic contents were also more distributed in PM1.1 with the great contents of secondary particles (NO3-, SO42-, and NH4+). Higher ratios of NO2/SO2 and NO3-/SO42- indicated that the vehicle emissions might be made more greater contribution rather than coal combustions to the fine particles. Crustal enrichment factors (EFcs) of trace elements (V, Cr, Ni, Zn, As, Se, Rb, Cd, Pb, and Bi) in PM1.1 in that called slight air pollution events were always higher than those in that called severe air pollution events and EFcs of Se were up to 2.5 × 104, while EFcs of Pb, Bi, and Cd were over 100. Based on kinds of elemental ratios in PM1.1 and PM1.1-2.0, atmospheric pollutants in Shanghai might be mainly from coal and oil combustions, diesel, and gasoline vehicles. Air masses backward trajectories also showed that the air masses from the northern part of China were one important air pollutant origins, but other ones might be the local sources, such as traffic and industries. Based on carcinogenic risk analysis of PM2.0, it was considerable that 12-60 children and 37-87 adults among millions of people living in Shanghai might be attacked by cancer during their lifetime. Moreover, the great carcinogenic risk was also observed according to the high concentrations of elemental Cr and As in PM1.1.