Research on the Origin and Source of Atmospheric Particulate Matter, Including Long-range Transport, Using Lead and Its Isotopic Ratios

Abstract

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.