| Abstrakt: |
A real-time air pollution monitoring campaign was conducted in Wuhan, the largest city in mid China, during the 2013 Spring Festival pollution episode. Analysis of chemical characteristics indicated that eight water soluble inorganic ions (WSIIs) and seventeen elements, respectively, accounted for 42.1% and 4.2% of PM2.5 mass. The study period was divided into three phases: the pre-holiday pollution phase (phase 1), the holiday pollution phase (phase 2) and the post-holiday pollution phase (phase 3). The ratio of Cl-/VK+ in phase 2 was 0.6, which was exactly equal to the value of firework-burning aerosol reported by Shen et al. (2009). Phase average concentrations of PM2.5, SO2, SO42- and K+ reached the highest in phase 2, whereas those of NCT, NO3-, Ca2+, and Mg2+ peaked in phase 3. K-mean cluster analysis and PMF were performed successfully to resolve seven sources of PM2.5 during the pollution period. Motor vehicle exhaust (25.0%) and coal combustion (21.6%) were the major contributors to PM2.5 mass followed by steel works (15.5%), secondary inorganic source (14.8%), firework burning (10.9%), glass/cement plants (6.5%) and road dust (5.7%). Additionally coal burning was the primary source of aerosol Pb in Wuhan during the study period. And the resolved sources of steel works and glass/cement plants mainly referred to the local sources in Wuhan. The results of health risk assessment from heavy metal indicated that As, Pb and Cd were the three main metals in PM2.5, which could cause non-carcinogenic effects. [ABSTRACT FROM AUTHOR] |
