Fine-particle pollution in large populated Asian cities can be very high compared with internationally accepted health goals. Much of this fine-particle pollution is produced by motor vehicles, fossil-fuel combustion, industrial processes and even windblown soils from desert regions. As part of a long term project in the Asian region with support from the IAEA, ANSTO has been using nuclear techniques not only to characterize fine-particle pollution, but also to quantify their sources and origins within Vietnam. Fine particles in ambient air are defined as those particles with aerodynamic diameters less than 2.5 μm in diameter. Particles in this size range can be directly absorbed into the blood stream from the lungs, are most efficient at absorbing and scattering visible light and can travel thousands of kilometres from their original source emission points. A full characterisation of these particles, their sources and their origins will help regulators better understand and hence control air-pollution issues in their countries. In 2002, the International Atomic Energy Agency (IAEA) established a Regional Cooperative Agreement (RCA) with 14 member states, including Australia, Bangladesh, China, India, Indonesia, the Republic of Korea, Malaysia, Mongolia, New Zealand, Pakistan, Sri Lanka, Thailand and Vietnam, to monitor, characterize and quantify sources of fine-particle pollution in each of these countries. This is a unique study as each country uses the same stacked filter samplers and has sampled at the same times each week for at least 5 years. The data obtained is unique for the region and will be picked up by a range of environmental agencies controlling and managing air pollution in each of the Member States as well as non-government organizations like the World Bank and the Asian Development Bank. It may be used to correlate medical conditions related to lung disease and XRF Newsletter, No. 23, September 2012

1) Agency’s Laboratories Seibersdorf, International Atomic Energy Agency, A-1400 Vienna, Austria 2) Faculty of Physics and Applied Computer Science, University of Science and Technology, 30-059 Krakow, Poland 3) Atominstitut der Oesterreichischen Universitaeten, TU Wien, Stationallee 2, A-1020 Vienna, Austria 4) Forschungszentrum Karlsruhe, Institute for Synchrotron Radiation, Postfach 3640, D-76021 Karlsruhe, Germany