Abstract
This study investigated the seasonal and daily variations of the total gaseous mercury (TGM) concentration in the ambient atmosphere, the correlation of TGM concentration with meteorological parameters (e.g., temperature, humidity, and wind speed) and criteria air pollutant concentrations (e.g., SO2, NOx, CO, O3, PM10, and PM2.5), as well as the transportation routes, at the Penghu Islands. The field measurement results showed that the average TGM concentration during the monitoring period was 3.17 ± 1.17 ng/m3, within the range of 1.17–8.63 ng/m3, with the highest concentration being observed in spring, while the TGM concentration typically increased in the morning, reached its peak concentration, and then started to decrease at nightfall. Moreover, the lowest average TGM concentration of 1.81 ± 0.15 ng/m3 was observed in summer, and this figure is close to the background TGM concentration of the Northern Hemisphere (1.6–1.8 ng/m3). The correlation analysis indicated that TGM concentration correlated positively with SO2, NOx, CO, O3, PM10, and PM2.5 and negatively with ambient temperature, relative humidity, and wind speed. In addition, the transportation route analysis showed that elevated TGM concentrations could be transported from either North China, East China, or South China to the Penghu Islands, while those originating from the South China Sea had the lowest contribution to the TGM levels at the Penghu Islands. Therefore, local sources and open burning might be mainly influenced by the long-range transportation of air masses, as the prevailing wind direction and air mass transportation routes potentially play critical roles in the variation of TGM concentration at the Penghu Islands.
Highlights
This study investigated the seasonal and daily variations of the total gaseous mercury (TGM) concentration in the ambient atmosphere, the correlation of TGM concentration with meteorological parameters and criteria air pollutant concentrations (e.g., SO2, NOx, carbon monoxide (CO), O3, PM10, and PM2.5), as well as the transportation routes, at the Penghu Islands
The field measurement results showed that the average TGM concentration during the monitoring period was 3.17 ± 1.17 ng/m3, within the range of 1.17–8.63 ng/m3, with the highest concentration being observed in spring, while the TGM concentration typically increased in the morning, reached its peak concentration, and started to decrease at nightfall
The results of correlation analysis showed that the TGM concentration was correlated positively with SO2, NOx, CO, O3, PM10, PM2.5 and negatively with ambient temperature, relative humidity, and wind speed
Summary
Mercury (Hg), one of the hazardous air pollutants (HAPs), is a persistent, toxic, and bio-accumulative heavy metal, and is currently regulated by the Environmental Protection Agency of USA (USEPA) and the United Nations Environment Programme (UNEP) (Nater and Grigal, 1992; Mason and Sheu, 1994; Schroeder and Munthe, 1998; Lin and Pehkonen, 1999; Boening, 2000; Mason and Sheu, 2002; Lin et al, 2005; Clarkson and Magos, 2006; Fu et al, 2010). Aerosol and Air Quality Research, 14: 364–375, 2014 elemental mercury (GEM), reactive gaseous mercury (RGM), and particulate mercury (Hgp) (Schroeder and Munthe, 1998; Lin and Pehkonen, 1999; Poissant et al, 2005; Feng and Qiu, 2008; Jen et al, 2012; Huang et al, 2013). GEM is the major species in the ambient atmosphere, which accounts for 95–99% of TAM with a residence time of 1.5–2.0 years in the atmosphere and can transport over great distances across continents (Schroeder and Munthe, 1998; Lin and Pehkonen, 1999; Fu et al, 2010; Jen et al, 2012). Long-range transportation and marine dissipation of mercury in the atmosphere has been identified as the predominant source at the background and the coastal regions (Ebinghaus et al, 1999; Blanchard et al, 2002; Sheu et al, 2010)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
