Analysis of high concentration of PM_2.5 at Seta hill, Shiga prefecture in 2013

Abstract

 Publication of PM_2.5 data in Shiga prefecture has been insufficient so far, and the actual situation of PM_2.5 isn't grasped.In this study, at Seta hill, Shiga prefecture, we continuously measured PM_2.5 concentration and analized the component of metals and inorganic ions. Trajectories of air masses were also calculated. It was deduced that one of the main causes of PM_2.5 high concentration at Seta hill was yellow dust(Asian dust). Elemental components (Al, Ca, Fe, Mg, Si) contained in yellow dust were detected from PM_2.5 collected in a yellow dust day. The results of inorganic ions analysis confirmed that SO₄^2- was more than NO₃^- and mainly distributed as (NH₄)₂SO₄ in the fine particles. The results of analysis of the chemical component and calculation of the trajectories of air masses showed that high concentrations of PM_2.5 except for yellow dust day were due to transboundary pollution from China and Korea, and anthropogenic SO₂ emissions from domestic urban areas and volcanic SO₂ emissions.