A method for estimating the fraction of mineral dust in particulate matter using PM2.5-to-PM10 ratios

Abstract A simple method for estimating the contributions of mineral dust to PM 2.5 , PM 10 , or TSP is presented. The method is based on the assumption of external mixing of two types of particles with different PM 2.5 /PM 10 ratios. The method was applied to local and transported dust events observed in Tsukuba, Japan, and was compared with collocated polarization lidar measurements. The method was then applied to three dust events that occurred in Oki, Rishiri, and Ochiishi, Japan, in 2012. The results showed that the method was useful for detecting mineral dust and for qualitatively describing the mixing of dust with anthropogenic aerosols.