Atmospheric Outflow of Anthropogenic Semivolatile Organic Compounds from East Asia in Spring 2004

Abstract

To estimate the emissions of anthropogenic semivolatile organic compounds (SOCs) from East Asia and to identify unique SOC molecular markers in Asian air masses, high-volume air samples were collected on the island of Okinawa, Japan between 22 March and 2 May 2004. Contributions from different source regions (China, Japan, the Koreas, Russia, and ocean/local) were estimated by use of source region impact factors (SRIFs). Elevated concentrations of hexachlorobenzene (HCB), hexachlorcyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs), and particulate-phase polycyclic aromatic hydrocarbons (PAHs) were attributed to air masses from China. A large proportion of the variation in the current-use pesticides, gas-phase PAHs, and polychlorinated biphenyl (PCB) concentrations was explained by meteorology. Chlordanes showed a technical mixture profile and similar concentrations regardless of source region. alpha/gamma HCH and trans/cis chlordane ratios did not vary significantly with different source regions and had regional averages of 2.5 +/- 1.0 and 1.2 +/- 0.3, respectively. Particulate-phase PAH concentrations were significantly correlated (p value < 0.05) with other incomplete combustion byproduct concentrations, including elemental mercury (Hg0), CO, NOx, black carbon, submicrometer aerosols, and SO2. By use of measured PAH, CO, and black carbon concentrations and estimated CO and black carbon emission inventories, the emission of six carcinogenic particulate-phase PAHs was estimated to be 1518-4179 metric tons/year for Asia and 778-1728 metric tons/year for China, respectively. These results confirm that East Asian outflow contains significant emissions of carcinogenic particulate-phase PAHs.

Atmospheric Short-Chain Chlorinated Paraffins in China, Japan, and South Korea

“…This phenomenon demonstrates that SCCPs were mainly influenced by local sources, even though other POPs in the atmospheres of Japan and South Korea have been shown to be affected by sources in China to a certain extent. 29,30 The calculated characteristic travel distances (CTD) of SCCPs, calculated using the OECD software tool, were approximately 600−900 km. 31 This relatively low long-range atmospheric transport potential could explain the observations of this present study.…”

Transpacific transport of benzo[a]pyrene emitted from Asia

“…The model results were compared with the observations at six monitoring sites including Changdao, Gosan, Kanazawa, Okinawa, Cheeka Peak Observatory (CPO), and Mount Bachelor Observatory (MBO) during different time periods when observations were actually conducted (Feng et al, 2007;Lee et al, 2006;Tamamura et al, 2007;Primbs et al, 2007;Killin et al, 2004;Primbs et al, 2008). A map of the location of these sites as well as a comparison of their measured concentrations is shown in Fig.…”

“…Many studies dedicated to investigating the episodic nature of transpacific transport indicate stronger transport of pollutants than background level under certain meteorological conditions (Lee et al, 2006;Tamamura et al, 2007;Primbs et al, 2007;Killin et al, 2004;Primbs et al, 2008). Transformation (ITCT 2K2) experiment was conducted over the West Coast of North America, and air masses containing pollutants originating from Asia were measured by aircraft over a region bounded by 32-44 • N, 122-125 • W, and 0-8 km altitude (Allan et al, 2004).…”

“…Surface concentration measurements combined with backward trajectories have shown that semi-volatile organic compounds (SVOCs), including PAHs, can be transported across the Pacific Ocean in about a week under certain meteorological conditions (Primbs et al, 2007;Primbs et al, 2008;Killin et al, 2004). For example, Killinet al (2004) observed significantly elevated concentrations of PAHs and other SVOCs during 15-16 March, 27-28 March and 22-23 April 2002, when backward trajectories passed over Asia, suggesting Asia as the potential source of these compounds.…”

A review of environmental and human exposure to persistent organic pollutants in the Pearl River Delta, South China

“…For both DDTs and HCHs, passive air sampling (Jaward et al, 2005) and back trajectory simulation of air masses (Primbs et al, 2007) showed that the PRD was one of the regions in East Asia that possessed the highest levels with elevated atmospheric outflows. Generally, almost all mean concentrations of DDTs in urban, suburban, and rural areas of the PRD were significantly higher than those observed at a rural site in Hong Kong (Table 1).…”