Inter-comparison of Seasonal Variation, Chemical Characteristics, and Source Identification of Atmospheric Fine Particles on Both Sides of the Taiwan Strait

Abstract

The spatiotemporal distribution and chemical composition of atmospheric fine particles in areas around the Taiwan Strait were firstly investigated. Fine particles (PM2.5) were simultaneously collected at two sites on the west-side, one site at an offshore island, and three sites on the east-side of the Taiwan Strait in 2013–2014. Field sampling results indicated that the average PM2.5 concentrations at the west-side sampling sites were generally higher than those at the east-side sampling sites. In terms of chemical composition, the most abundant water-soluble ionic species of PM2.5 were SO42−, NO3−, and NH4+, while natural crustal elements dominated the metallic content of PM2.5, and the most abundant anthropogenic metals of PM2.5 were Pb, Ni and Zn. Moreover, high OC/EC ratios of PM2.5 were commonly observed at the west-side sampling sites, which are located at the downwind of major stationary sources. Results from CMB receptor modeling showed that the major sources of PM2.5 were anthropogenic sources and secondary aerosols at the both sides, and natural sources dominated PM2.5 at the offshore site. A consistent decrease of secondary sulfate and nitrate contribution to PM2.5 suggested the transportation of aged particles from the west-side to the east-side of the Taiwan Strait.

Characteristics of Atmospheric PM2.5 in a Densely Populated City with Multi-Emission Sources

“…The possible cause of lower levels in summer is the intermittent precipitation which removes the primary PM 2.5 and secondary precursors such as SO 2 , NO x and VOCs. Similar observation has been reported elsewhere by (Li et al, 2016).…”

“…On the other side, the NOR values were 0.16-0.24, 0.0002-0.0014, 0.08-0.29 and 0.11-0.19 for spring, summer, autumn and winter, respectively. The low values of NOR and SOR for summer show that the potential for secondary formation of NO 3 -and SO 4 2-were low and mostly were sourced from local, pollution while it was high for spring, autumn and winter which shows the potential to convert SO 2 and NO x to particulate form via secondary transformation (Zhou et al, 2009;Li et al, 2016). This can also be attributed to lack of favorable conditions such as low PM 2.5 concentrations reported earlier or low abundance of nitrogen due to the loss of NH 4 NO 3 at high temperatures (Zhou et al, 2009;Wu et al, 2015).…”

“…The SOR indicates the degree of oxidation of sulfur in terms of the ratio of sulfate to total sulfur in SO 4 2-+ SO 2 . The NOR indicates the degree of oxidation of nitrogen in terms of the ratio of nitrate to total nitrogen in NO 3 -and NO x and if values of SOR and NOR are 0.25 and 0.1 is an indication of high potential for the oxidation leading to secondary inorganic aerosol formation in the atmosphere (Li et al, 2016).…”

“…Particulate matter, with an aerodynamic diameter less than 2.5 µm (PM 2.5 ), has been categorized as fine particulate matter. This category of particulate matter has attracted the interest of researchers, scientists and regulators due to its possible effects on the human health and the environment especially visibility and climate change (Ho et al, 2006, Wang et al, 2015aWang et al, 2015b;Li et al, 2016). Due to its size, the PM 2.5 can easily penetrate the human respiratory systems a as well as across the circulatory system posing great risk in form of respiratory diseases and cardiovascular complications including lung cancer (Bell, 2012;Xu et al, 2012).…”

Inter-comparison of Chemical Composition and Originality of Atmospheric PM10 at Coastal Regions and Offshore Islands in the Subtropical East Asia

“…Posterior to PM 10 sampling, aluminum foil was used to fold each quartz fiber filter, which was temporarily stored at 4 °C and then transported back to the Air Pollution Laboratory of Institute of Environmental Engineering at National Sun Yat-Sen University for further chemical analysis within 1 week. The sampling and analytical procedure was similar to that described in various previous studies (Cheng and Tsai 2000;Lin 2002;Yuan et al 2006;Tsai et al 2008Tsai et al , 2010Li et al 2015Li et al , 2016. Both field and transportation blanks were undertaken for PM 10 sampling, while reagent and filter blanks were applied for chemical analysis.…”