Contribution of Asian outflow to atmospheric concentrations of sulfate and trace elements in aerosols during winter in Japan

Evaluation of long-term trend of atmospheric lead pollution in western Japan based on lead isotope ratios and Pb/Zn ratio as indicators of long-range transport of aerosols from the Asian continent

“…In contrast, the differences in the locations of the study sites may contribute to the differences in their atmospheric lead concentration and isotope ratios if the amount and sources of lead transported from the Asian continent are different among the sites, depending on their locations. Sakata et al (2014) found that the atmospheric trace element concentrations at the sites along the coast of the Sea of Japan decreased exponentially with increasing longitude of their locations. Hence, it is probable that the lead concentrations at the Hirado and Matsuura sites are higher than those at the Oki and Matsue sites located in the east.…”

“…The typical operating conditions for ICP-AES used in this study were 1,200 W for RF power and 15 L min − 1 for plasma flow rate. Its precision and accuracy in measuring elements, including lead and zinc, were already verified using a NIST standard reference material (urban particulate matter, SRM1648; Sakata et al, 2014). The aerosol concentrations of lead and zinc were corrected with respect to those in blank filters.…”

“…Kaneyasu et al (2014) reported that the Pb/Zn ratio of aerosols collected in Fukuoka in western Japan was close to that in Beijing. Sakata et al (2014) measured the concentrations of trace elements, including lead and zinc, in aerosol samples from 10 sites (four sites from industrial and urban areas and six sites from remote areas) across Japan from April 2004 to March 2006. Using these data, we calculated 0.30 ± 0.09 as the average Pb/Zn ratio ( ± 1σ) in 10 sites during summer, which was the time when the contribution of sources in China was minimized.…”

“…The aerosol samples from the Oki site were collected on cellulose membrane filters or PTFE filters using a handy-type, high-volume air sampler, which has an impactor to trap coarse particles larger than 10 μm (Mukai et al, 1994). In contrast, the samples from the Matsue and Matsuura sites were collected on quartz fiber filters by the same method as that used for the samples from the Hirado site (Marumoto and Sakata, 2007;Sakata et al, 2014). We assumed that the differences in the materials of filters have a little effect on the concentrations of lead and zinc in aerosols.…”

Contributions of Long-Range Transported and Locally Emitted Nitrate in Size-Segregated Aerosols in Japan at Kyushu and Okinawa

“…Pb is mainly derived from coal combustion. Sakata et al (2014) reported that the concentration of Pb is strongly related to its emissions in the regions over which the air mass passed, particularly in the 30-40°N region of China, which is one of the highest emission areas in China. The annual consumption of coal in China amounted to 50% of total worldwide coal consumption in 2015 (BP Statistical Review of World Energy, 2016).…”