Temporal and Spatial Characteristics of Mercury Contained in Size-Fractionated Particles in Shanghai Ambient

Size-fractionated particles were collected at campus site and mixed zone. Mercury extracted from size-fractionated particles by wet digestion and thermal decomposition was analized by cold vapor atomic absorption method. The volatile particulate mercury (VPM), reactive particulate mercury (RPM) and ~inert particulate mercury (IPM) were differentiated by two-steps-extraction. Results indicated that more than 90% of mercury in TSP in Zhabei district was in particles with a size less than 8 μm, while ~50%～ 60% was found in campus site. Particulate mercury in winter is clearly larger than that in other seasons, and IPM has the larger ratio in finer particles, which indicates that particulate mercury speciation is associated with its formation mechanism. No strong correlation of mercury concentration with ~ ~207 Pb/~ ~206 Pb, ~ ~208 Pb/~ ~206 Pb ratios is found, while ~ ~207 Pb/~ ~206 Pb and ~ ~208 Pb/~ ~206 Pb are relatively close to those of the particles ~exhausted from coal burning and soil, so it suggests that coal burning and suspended dust might be the ~important contributors. Preliminary anthropogenic emission inventory of atmospheric mercury suggests that coal burning might be the main sources.