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Past Fresh Scientists
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Fresh Science 2000 Air pollution: size counts
A study of
atmospheric particles in Australian cities has provided new information on tiny
particles that are believed to be most dangerous to human health. The
research, carried out by Dr Melita Keywood from CSIRO, has identified for the
first time in Australia the chemical make-up of different sized particles in the
air. Tiny particles, which can penetrate deep into the lungs, contain toxic and
cancer-causing chemicals. The chemicals include lead, black carbon and complex
organic compounds. The
research compared atmospheric particles in Australian cities using the same
measurement technique at all sites. In the past, comparisons of particle levels
in air have been difficult as State and Territory agencies use different
instruments and different techniques for measuring pollution. Particles
in the air come from motor vehicles emissions, domestic wood burning, industry
and natural sources, and often contribute to haze as well as health problems.
Particles range in size from large (greater than 10 micrometres) to very
small (less than 0.01 micrometre). Dr Keywood
and colleagues measured levels of particles smaller than 10 micrometres in
diameter in Sydney, Melbourne, Adelaide, Brisbane, Canberra and Launceston
during seasons in which air pollution was expected to be most severe. Sydney,
Brisbane, Melbourne and Adelaide had average particle concentrations of between
20 and 25 micrograms per cubic metre. Despite
the cities’ smaller sizes, average concentrations in Canberra and Launceston
were two- to three-times greater than in the other four cities, with smaller
particles making up a larger proportion of the particle concentration in
Launceston and Canberra. ‘At
times, particle levels in Canberra and Launceston are amongst the highest in
Australia,’ says Dr Keywood. ‘Domestic
wood fires in winter, combined with light winds and the locations of the two
cities in valleys, cause high pollution readings,’ says Dr Keywood. The Australian air quality standard for particles is based on concentration of all particles smaller than 10 micrometres. However, the particles that harm us most are believed to be those well below 10 micrometres in size. This research has shown that these smaller particles do contain some of the toxic and carcinogenic chemicals of concern to human health. Tiny particles are more likely than larger particles to be responsible for adverse health impacts with elderly and children most at risk, along with people having existing respiratory illnesses. The results of this work and those from other studies provide important input to the ongoing development of air quality standards, thus potentially reducing the health risk associated with exposure to air pollution. Dr
Keywood’s research was sponsored by Environment Australia and performed by
CSIRO in collaboration with ANSTO. E-mail: melita.keywood@dar.csiro.au ScienceNOW! was founded three years ago to bring leading edge science directly to the media, students and the general public. It provides a national forum where young scientists explain their work and interact with the audience to make science interesting, relevant and accessible. ScienceNOW! 2000 runs from 4 to 7 May 2000. Sixteen scientists, selected by national competition, will present their work. One of them will win a scientific visit to the UK sponsored by the British Council. ScienceNOW! is sponsored by the Victorian Department of State and Regional Development and the Commonwealth Department of Industry, Science and Resources.
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Media contacts:
Niall Byrne 0417 131 977 and Sarah Brooker 0413 332 489
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