What’s in our pollution?
- Soot, elemental carbon 25%
- Ammonium sulfate 25%
- Hydrogen and oxygen 25%
- Seaspray 10%
- Water vapour/trace elements 10%
- Soil 5%
The Australian Nuclear Science and Technology Organisation (ANSTO) is set to collect and analyse tiny particles of smog - in Sydney, Melbourne, Brisbane, Perth, Adelaide and Hobart - in a project which aims to determine exactly what our citydwellers are breathing.
Staff from ANSTO’s Physics Division are setting up aerosol sampling units in each of these cities to determine the amount (and chemical composition) of smog over an annual period. Particles smaller than 2.5 millionths of a metre, which are suspended in our air as smog, have been associated with health problems such as asthma, respiratory conditions and heart disease.
ANSTO will work with universities and other government agencies in the $332,800 project to be funded by the Commonwealth Air Toxics Program and the Natural Heritage Trust. Coarser particles, (larger than 10 millionths of a metre) which also contribute to visual pollution will be monitored by other agencies.
Dr Brian Spies, Head of ANSTO’s Physics Division, said the sampling unit is basically a large grey box with a tube running up the side. The fine particles are collected weekly on 25mm diameter teflon filters.
"These filters often turn black with the collected contaminants, and are analysed at ANSTO using ion beams from our three-million-volt Van de Graaf Ion Beam Accelerator. We can measure up to 35 elements simultaneously using our nuclear analysis techniques," Dr Spies said. "Other organisations in Australia measure air pollutants such as gases, but only we can look at the elemental composition of the very fine smog particles in each sample. The results provide important information for environmental and health studies."
Dr Spies said that this project would be important as a comparative study of Australian cities, and as a systematic way of measuring changing pollution patterns over the course of a year.
Air pollution can change considerably with the seasons depending on the source of the pollution.
"We know that different cities are affected differently. By taking samples every six days, we will be able to accurately measure changing patterns."
ANSTO has ten years’ experience sampling and analysing fine particle dust in various states of Australia and eight countries around the world.
"These previous studies have found a variety of substances in the air of Australian cities, including soot, elemental carbon, ammonium sulfate, sea spray, trace elements and soil," he said.
Published: 05/05/2002