Highly Time-Resolved Atmospheric Observations Using a Continuous Fine Particulate Matter and Element Monitor

We measured the fine particulate matter (PM2.5) and element (S, Pb, K, Si, Ca, Fe, Mn, and Zn) concentrations in March 2015 using a continuous PM2.5 mass and element concentration monitor at Sanyo Onoda, which is located in the western part of Japan. In addition to the PM2.5 concentration measurements, this instrument can continuously and automatically analyze the elements in PM2.5 without sample pretreatment using X-ray fluorescence at a high time resolution. The PM2.5 concentrations measured with our apparatus and the system from the Yamaguchi Prefectural Government had a good correlation, with a correlation coefficient of 0.931. The increase in the PM2.5 concentration in the case of the westerly wind indicates that the air mass includes a high concentration of particulate matter that is transported from the Asian continent. The anthropogenic components (S, Pb, and K) showed a strong correlation with PM2.5. However, there was a moderate correlation between the crustal components (Si, Ca, and Fe) and PM2.5. During a high PM2.5 concentration event, the results of the time lag in the peak between the anthropogenic components and the crustal components indicate that the distinct air masses were transported from different origins. The Pb/Zn ratio increased with PM2.5, which might be a useful indicator for evaluating the long-range transport.