Particulate Matter Source Apportionment: An Overview and Summary of Current Asian Studies

Abstract

S-29C3-2 Background/Aims: An extensive literature review was conducted to evaluate the sources, composition, and ratios of particulate matter (PM) air pollution in Asian cities as part of a broader review of the literature on the health effects of air pollution in developing Asia. Methods: The reviewed air quality studies were published between 1995 and 2009 and were conducted in 16 Asian cities representing major urban conglomerates and background sites. Each reviewed study used receptor-based methods that include the following: Chemical Mass Balance Analysis, Principal Component Analysis, Positive Matrix Factorization, or other accepted chemical speciation methods. Results: The results obtained from these studies were regrouped into 6 different categories of sources that include: mobile, stationary, biomass, fugitive, secondary, and other. The highest fine PM concentrations were observed in Beijing, Hanoi, Delhi, and Kolkata reaching over 100-μg/m3 (annual average). There was great variation of source contribution by city suggesting the differences among the cities' PM problem. For some major cities, the ratios of PM2.5 to PM10 were calculated. South Asian cities seemed to have a higher coarse fraction in their PM compared to East Asian cities. In the South Asian cities of Dhaka, Rajshahi, Chennai, Islamabad, and Chak Shahzad, the ratios of PM2.5–PM10 were in the range of 0.22 and 0.35 illustrating that the coarse fraction dominated because of resuspended road dust, soil dust, and uncontrolled construction particles. With progressive development in recent years, this ratio is probably shifting to equal portion of both fine and coarse fractions as seen in many East Asian cities. In Bangkok, Beijing, Taiwan, and Bandung, the fine fraction slightly dominated the coarse fraction as vehicle emissions and industrial activity have progressively increased in the last decade. In more developed countries such as South Korea and Japan, this ratio was as high as 0.77. Conclusion: Together, the fine to coarse fraction PM ratio, the source contributions of PM, and the amount of fossil fuel burning and/or associated stage of development, provide a foundation for understanding the potential health risk and air quality status for some of these Asian cities. This work was funded by the Health Effects Institute.