Particuology

Volume 28, October 2016, Pages 114-120

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

https://doi.org/10.1016/j.partic.201509005 Get rights and content

Highlights

  • •
    A method using the PM2.5/PM10 ratio to estimate dust fraction in PM2.5 was presented.
  • •
    Estimated dust fraction was consistent with lidar depolarization ratio measurements.
  • •
    The method is useful for indicating dust and its mixing with anthropogenic aerosols.

Abstract

A simple method for estimating the contributions of mineral dust to PM2.5, PM10, or TSP is presented. The method is based on the assumption of external mixing of two types of particles with different PM2.5/PM10 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.

Introduction

Environmental standards for PM2.5 (particulate matter with diameters of 2.5 μm or less) have been enacted in Japan, China, and Korea; and monitoring of PM2.5 has become common at environmental monitoring stations. In East Asia, deserts and urban and industrial areas are located close together, so anthropogenic aerosols and Asian dust often coexist (Li et al., 2010, Onishi et al., 2012, Sugimoto et al., 2013). For the regulation of PM2.5, it is important to know the contribution of Asian dust. PM2.5 is measured at the same time as PM10 or suspended particulate matter (SPM: the Japanese environmental standard for particulate matter that approximately corresponds to PM7) at many of the environmental monitoring stations. It is practically useful to use both PM2.5 and PM10 (or SPM) for characterizing aerosols.
In this paper, we present a method for using PM2.5-to-PM10 ratios to estimate the fraction of Asian dust in PM2.5, PM10, and total suspended particulate (TSP). The method is a simple partitioning based on the assumption of two distinct aerosol types mixing, those having high PM2.5-to-PM10 ratios (fine mode dominant aerosols that correspond to anthropogenic aerosols) and low PM2.5-to-PM10 ratios (coarse mode dominant aerosols that correspond to Asian dust). We applied this method to measurements from Tsukuba, Japan, where we had collocated polarization lidar measurements, and compared the results with those from dust estimations based on a similar partitioning method that used lidar depolarization ratios (Shimizu et al., 2004, Sugimoto et al., 2003). We then applied the method to the PM2.5 and PM10 data for dust events of 2012 shared for study in Working Group 1 on Asian dust under the Tripartite Environmental Ministers Meeting among Japan, China, and Korea (TEMM WG1).

Section snippets

Methods

We considered a mixture of two aerosol types, fine mode dominant aerosols (anthropogenic aerosols) and coarse mode dominant aerosols (Asian dust). The conceptual size distributions of the two types are illustrated in Fig. 1.
If f10 and c10 denote the PM10-to-total mass ratios for the fine and coarse mode dominant aerosols, respectively, and f2.5 and c2.5 denote the PM2.5-to-total mass ratios for the fine and coarse mode dominant aerosols, respectively, then PM2.5 and PM10 can be defined as:PM2.5=

Local and transported dust in Tsukuba, Japan

Collocated PM10, PM2.5, and lidar measurements were performed in Tsukuba, Japan (36.05° N, 140.12° E). PM10 and PM2.5 were measured using the beta-particle absorption method. The lidar was a polarization-sensitive (532 nm) two-wavelength (1064 and 532 nm) system that was part of the Asian Dust and Aerosol Lidar Observation Network (AD-Net) (http://www-lidar.nies.go.jp/AD-Net/). AD-Net is a contributing network to the WMO GAW Program (http://www.wmo.int/pages/prog/arep/gaw/gaw_home_en.html).
In March

Conclusions

We have presented a simple method for estimating the dust fraction in PM2.5, PM10, and TSP using PM2.5-to-PM10 ratios. Comparisons with polarization lidar measurements showed that the method was useful for detecting dust events and for indicating the qualitative mixing of dust and anthropogenic aerosols.
The PM2.5/PM10 method is a simple, one-parameter method, and there is no room for improving the method itself. However, knowledge of the climatology of aerosols at each measurement location

Acknowledgments

This paper contributes to Joint Research on Dust and Sandstorms under TEMM-WG1. The study was supported in part by the Environment Research and Technology Development Fund of the Ministry of the Environment, Japan (5B-1202 and 5-1502).

References (19)

There are more references available in the full text version of this article.

Cited by (79)

  • Spatial-temporal variations and mineral dust fractions in particulate matter mass concentrations in an urban area of northwestern China

    2018, Journal of Environmental Management
    Citation Excerpt :

    The method is a simple partitioning based on the assumption of two distinct aerosol types mixing, those having PM2.5-to-PM10 ratios, which provides insights into source characterization of atmospheric particles (Sugimoto et al., 2015; Chen et al., 2017b; Ishak, 2016). Thus, the PM2.5-to-PM10 ratio model is a new method for approximated quantification the contribution of dust storm particles to the total PM in East Asia (Sugimoto et al., 2015). In China, most research on PM spatial-temporal distributions and PM atmospheric sources has focused primarily on developed areas in eastern China such as the Beijing–Tianjin region (Zhao et al., 2013), the Yangtze River Delta (Hu et al., 2014) and the Pearl River Delta (Ho et al., 2014).

  • Seasonal characteristics and particle-size distributions of particulate air pollutants in Urumqi

    2019, International Journal of Environmental Research and Public Health
View all citing articles on Scopus
☆
This article is one of the outcomes of the activity of the working group I (WGI) for joint research on dust and sand storms under the Tripartite Environment Ministers Meeting (TEMM) among China, Japan and Korea.
View full text
© 2015 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.