Characteristics and Sources of Speciated Atmospheric Mercury at a Coastal Site in the East China Sea Region

Abstract

Atmospheric mercury is a global concern due to its ability of long-range transport. In order to understand the characteristics and sources of speciated mercury in the East China Sea region, a coastal monitoring site was established on Chongming Island in Shanghai, China. Total gaseous mercury (TGM), reactive gaseous mercury (RGM) and particulatebound mercury ( , respectively. TGM has a sharp increase at 5:00 in the morning and reaches peak at about 8:00, which is probably caused by the downward mixing of enhanced TGM aloft originated from regional sources. Wind roses suggest that urban Shanghai area has a considerable contribution to TGM in Chongming. Repartitioning of reactive mercury from particles to the air under the influence of air temperature could be one major source of RGM. Four heavy mercury pollution episodes were selected for source analysis. Mercury pollution in the summer event is mainly from the southwest direction with high ∆TGM/∆CO ratio and has the most influence on the North China Plain (NCP) region. The winter event is mainly under the influence of industrial pollution from the NCP region. The autumn event is contributed by both industrial pollution and biomass burning in North and Northeast China exhibiting a lower slope of ∆PHg/∆TGM. Springtime Asian long-range transport (ALRT) is crucial to the mercury background of North America. However, in the spring event identified in this study the mercury outflow from low altitude through East China mostly ascended to high altitude during the transpacific airmass transport. This provides an important incentive for future studies to focus on the way of mercury outflow from East Asia.

Impacts of Anthropogenic Emissions and Meteorological Variation on Hg Wet Deposition in Chongming, China

“…The 1 • × 1 • gridded meteorological data from the Global Data Assimilation System were used in this study. The endpoint was set at the sampling site with a height of 500 m above sea level, representing the center of the boundary layer [19].…”

“…The downtown area of Shanghai is 50 km southwest of the sampling site. Thus, the wet deposition flux here could reflect the background concentrations of the YRD region and many atmospheric observations have been conducted at this station over the years due to its remote environment [19].…”

“…The anthropogenic atmospheric Hg emissions increased in the YRD region due to enhanced energy consumption during the winter [37]. The high PM 2.5 concentrations resulted in more GEM oxidation with higher GOM/PBM concentrations [19,38]. Meanwhile, airmass from northern China and Mongolia resulted in cold and dry weather with less rainfall in Chongming during winter.…”

Study on Mercury in PM10 at an Urban Site in the Central Indo-Gangetic Plain: Seasonal Variability and Influencing Factors

“…Studies employing field measurements and multiscale model analysis (Bieser et al, 2014), in polluted regions in Asia (Fu et al, 2011;Xu et al, 2015;Zhang et al, 2017), Europe (Li et al, 2008;Pyta and Rogula-Kozłowska, 2016), and the United States (Song et al, 2009;Gratz et al, 2013;Jiang et al, 2013) have reported significant spatiotemporal variability in atmospheric HgP concentrations. For example, HgP concentrations are considerably higher in areas with abundant refineries, iron and steel manufacturing, power plants, chemical plants, coal-fired utility plants, and road traffic (Landis et al, 2002;Zhang et al, 2015;Siudek et al, 2016;Cheng et al, 2017;Li et al, 2017;Lewandowska et al, 2018).…”