We have summarized the characteristics of Pb in terms of the Pb/Zn ratio and lead isotopic ratios related to the long-range transport of air pollutants from Asian countries based on our research. We evaluated the impact of China since the 1990s using many international papers and reports from China. In the 1990s, Chinese air was characterized by a high Pb/Zn ratio and higher ²⁰⁸Pb/²⁰⁶Pb and ²⁰⁷Pb/²⁰⁶Pb ratios. However, the Pb/Zn ratio and lead isotope ratios were found to change after 2000 due to the phase-out of leaded gasoline in China. After 2006, the Pb concentration in the air decreased in China, and the Pb isotope ratio also changed more radiogenically. The present regional characteristics of the lead isotope ratios in the Asian region have greatly changed compared to that of the 1990s. We proposed a new map of the lead isotope ratios for the long-range transport study around Japan in this review article.

Continuous observations of organic nitrates were conducted from February to May 2022 at Fukue Island, Nagasaki, Japan. The average concentrations of PNs (Total peroxy nitrates) and ONs (Total organic nitrates) during the observation period were 0.44±0.33 and 0.26±0.14 ppbv (1σ), respectively. The air mass origins arriving at Fukue were classified into the following seven groups: Russia, Northern China (NC), Korea, Northern China/Korea (NC+KR), Southern China, Japan, and Ocean, using backward trajectory analyses, and the concentration variations for each air mass origin were investigated. In February and March, PNs and ONs concentrations from NC were the highest of the seven air mass origins. In April and May, however, PNs and ONs concentrations from NC decreased, while those from NC+KR were the highest. Such concentration variations would be attributed to the relationship between the atmospheric lifetime and the transport time from the Asian continent to Fukue. In April and May, the air masses from NC have long transport times and most of PNs would be lost before arriving at Fukue Island, while the air masses from NC+KR have shorter transport times than those from NC, and the percentage of PNs loss during the transport would be low.