Air Quality Monitoring
Scientists at GNS Science use a range of ion beam analysis techniques to determine airborne particle elemental composition and to identify and quantify sources of air particulate matter.
Air particles 10 microns in diameter or smaller are a threat to human health. At GNS Science, scientists are using specialised equipment designed and built at the GNS Science Ion Beam analysis facility in Lower Hutt, New Zealand, for semi- automated analysis of particulate matter from air filters. By bombarding the atoms of an air particulate sample with ions of sufficient energy, typically protons or alpha particles, we can detect the emitted X-rays, Gamma-rays and other energy signatures characteristic of the elements present in an air sample. The compositional analysis of particulate matter is used to identify sources of particulate matter pollution and their contribution to PM mass concentrations, it also provides screening for trace elemental species (As, V, Ni, Cr, Hg, Pb…) and organics (e.g. PAHs) that may be a health concern.
GNS Science has been working closely with regional councils and unitary authorities for many years to provide both analytical services and planning advice. One recent example is the finding that atmospheric concentrations of arsenic, a known carcinogen, are above national and international guidelines in a number of New Zealand urban centres.
The main source of elevated arsenic levels is the burning of treated timber in domestic fires and, consequently, the highest atmospheric levels are occurring in winter. In some cases, atmospheric concentrations have reached twice the upper guideline for human health. Most local councils already ban the burning of CCA-treated timber, however the findings mean more work needs to be done in this area. The detection and source appointment of air pollution provide crucial information for councils to form and evaluate air quality monitoring policies, community education programmes and enforcement effort.
Ion beam air particulate elemental analysis is non-destructive, cost-effective and faster than conventional chemical methods. Moreover, ion beam analysis can detect a wider range of elements, including lighter elements such as hydrogen and sodium that are difficult to detect using other methods. Since 1998 GNS Science has analysed more than 40,000 air samples from monitoring stations in New Zealand and overseas, providing crucial information for better management of air quality.
Sources of air pollution in Ulaanbaatar
GNS Science participates in the IAEA (International Atomic Energy Agency) Regional/Cooperative Agreement air monitoring programme for Australasia and South East Asia. One example of our international projects is the collaboration with the National University of Mongolia to determine sources of air pollution in Ulaanbaatar, the capital city of Mongolia.
GNS Science advised Mongolian researchers on appropriate sampler installation and operation. We then analysed the filter samples collected from Ulaanbaatar at GNS Science, to identify sources and mass contributions of particulate air pollution.
The analysis results revealed that dust from surrounding deserts and the urban area were the biggest contributors to air particulate pollution in Ulaanbaatar. Coal burning by power stations and residents for home heating was found to be the major source of fine particles during winter months, a result that has significant health implications for the local population. Specialised analysis also identified long range sources due to forest fires and industrial emissions from other countries that also contributed fine particles to air pollution in Ulaanbaatar.
This body of knowledge allows the Mongolian government to make informed policy decisions for controlling air particulate pollution that aims for a cleaner future and a healthy population.
For more information, please contact:
Joe Manning, Head of Department, Materials and Air, GNS Science