Air quality in Penghu county, Taiwan

Last modified: 
14/4/2017
To be updated

Hg

In the 2015 Taiwanese master thesis of 陈帝文 (transliterated Chen Diwen) with advisor 袁中新, conducted at the Institute of Environmental Engineering of the National Sun Yat-sen University, which studied atmospheric speciated mercury at Penghu during the four seasons of 2013, it was claimed that, during the summer, atmospheric mercury concentrations were much lower than during other seasons due to the fact that contaminated air masses were blown mainly from South China Sea and the Philippines, which had less combustion source emissions. During the fall and winter, the industrial emissions from the west-coast of mainland china, as well as air mass laden mercury contaminants from the Korea Peninsula reached Penghu by the prevailing monsoon long-range transport of mercury. The concentrations of atmospheric mercury as gaseous mercury (TGM) was highest in spring, followed by winter, fall and summer respectively. The seasonal variation of gaseous oxidized mercury (GOM) concentrations was highest in summer, followed by spring, winter and fall respectively; while particulate mercury (PHg) concentrations were highest in spring, followed by winter, summer and fall respectively.1

Comparison with Mt. Lulin

Mt. Lulin Meteorological Station is located at the intersection of Nantou and Chiayi Counties, in Central Taiwan, at a longitude of 120°52'25"E, latitude of 23°28'07"N, and altitude of 2,862m. The Penghu Air Quality Sampling Station is located on the same latitude, but not on a high altitude. Whereas the Mt. Lulin station is not immediately surrounded by anthropogenic sources of pollution, the Penghu Air Quality Sampling Station is located in suburban Makung City, featuring anthropogenic sources of pollution such as automobiles and fishing boats. Further more, the Penghu Islands are situated on the pathway of long-range transport between the territory of the People's Republic of China and the Republic of China (Taiwan).

In 2016, seven researches from seven different Taiwanese research institutes jointly wrote a paper in "Aerosol and Air Quality Research", trying to understand the different mechanisms at work in either of these two locations: The field monitoring of atmospheric mercury, criteria air pollutants and meteorological parameters during the four seasons was undertaken from March 2011 to February 2012. The data on ambient air quality and meteorological parameters monitored at the two remote sites were further applied to the correlation analysis, to investigate the transportation modes between these two remote sites. In this study, PM10 concentrations were routinely measured by β-gauge monitors, which is in accordance with the US EPA-designated equivalent methods (No. EQPM-0391-081). The PM10 inlet is a cyclone operated at the sampling flow rate of 18.9 L min–1. Gaseous air pollutants were monitored by the Taiwan Air Quality Monitoring Network (TAQMN). A monitoring protocol of ambient gaseous air pollutants including O3, SO2, CO and NOx was conducted instrumentally at 3m level above the ground. The authors concluded: The concentrations of air pollutants monitored at Mt. Lulin were generally lower than those at the Penghu Islands, with the exception of O3 concentration. PM10 and NOx were the important factors that can distinguish two clusters of measurement data at the two remote sites, and a criteria discriminant factor of atmospheric parameters derived from these two air pollutants. For both high- and low-frequency patterns, the concentrations of NOx and PM10 exhibit significant differences between the two remote sites. However, O3 concentrations showed almost no differences between these two remote sites, implying that the pattern for the formation and transportation of O3 at these two sites resulted from similar mechanisms. Moreover, atmospheric mercury (TGM) had a very good linear correlation with CO. The diurnal variation of Hg concentration was dramatic at the Penghu Islands, while it appeared as low as the North Hemisphere background mercury concentration at Mt. Lulin, indicating that they were not formed via the mechanism modes.2

  • Caption: Seasonal variation of air pollutants at the two remote sites for (a) carbon monoxide, (b) nitrogen dioxide, (c) ozone, and (d) sulfur dioxide.
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  • Caption: Low-frequency seasonal variation of atmospheric mercury (TGM) between two remote sites.
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To be updated

Footnotes

  • 1. http://www.airitilib..., Temporospatial Distribution of Atmospheric Speciated Mercury and Their Chemical Characteristics at the Penghu Islands (澎湖群島大氣汞污染物濃度時空分佈及化學特徵分析) (Thesis). 2015.
  • 2. http://aaqr.org/VOL1...

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