Total Mercury and Particulate-Bound Mercury Concentrations and Content in Ambient Air in Central Taiwan

Total gaseous mercury (TGM) concentration in ambient air, particulate-bound mercury concentrations and particulate-bound mercury contents in total suspended particles (TSP) from locations in Central Taiwan were measured and discussed relative to their ranges and potential sources. Meteorological conditions in terms of average temperature, wind direction, wind speed, and humidity were also monitored at a traffic sampling site in Sha-Lu central Taiwan from July 2011 to November 2011. The results revealed that the average concentrations of total gaseous mercury (TGM) and particulate-bound mercury in TSP were 8.73 +/- 5.53 (ng/m3) and 0.000164 +/- 0.00007 (ng/m3), respectively. The monthly average TGM concentrations were highest in July (17.50 +/- 4.79 ng/m3) and lowest in November (4.10 +/- 0.72 ng/m3). The monthly average particulate-bound mercury concentrations were highest in July (0.000293 +/- 0.00021 ng/m3) and lowest in November (0.000109 +/- 0.00002 ng/m3). The average particulate-bound mercury Hg(p) contents were 0.15 (ng/g), while the monthly average particulate-bound mercury contents were highest in July (0.26 ng/g) and lowest in November (0.11 ng/g). In summer, industrial activities, especially smelting activities, were an important source of atmospheric Hg (Fu et al., 2009). Therefore, high mercury concentrations were observed in July and August. Several main sources of Hg emissions have also been identified in the study area.