14 September 2009
Tasmania's air quality monitoring network has tracked dust deposits from the Simpson Desert and possibly other parts of the mainland covering a wide part of Tasmania over the weekend.
EPA Director Warren Jones said during Saturday the 12th and Sunday the 13th of September, the Baseline Air Monitoring Network of the EPA Tasmania (BLANkET) detected significant levels of particles in the ambient air.
"The elevated readings were present in air station data from the north and south of the state from the early hours of Saturday," Mr Jones said.
"The instrument readings indicated the particles were too big to be from smoke, but were possibly due to dust."
"A very large and well defined peak in the signals occurred on Saturday evening, around 9 pm on Saturday night in Launceston, and about 1 hour later in Hobart."
"Instruments at the major air stations in George Town and Rowella also detected this event, as did the five BLANkET air stations in the north-east of the state."
Mr Jones said on Monday the 14th of September, the DustWatch Team of the New South Wales Department of Environment and Climate Change informed officers assisting the EPA in Tasmania that a large dust storm from the Simpson Desert injected significant quantities of dust into the atmosphere, which was carried south to the ocean and then eastward over Tasmania and into the Tasman sea.
There have been reports of dust deposits over Tasmania, particularly along the north and east coasts.
Mr Jones said the Hobart office of the Bureau of Meteorology reported very strong upper level north-westerly winds on Saturday, reaching a peak of more than 160 km/hr at 9 pm on Saturday night at the 10,000 feet level.
Mr Jones said the BLANkET monitoring network was established primarily to monitor smoke from planned burns and wood heaters but it also has the capacity to be useful in monitoring and tracking particle pollution from other sources including dust and smoke from interstate.
"It also needs to be noted that the air quality data available for the 12th of September for Hobart and Launceston at present are indicative only, and cannot be used to determine if the dust levels on this day exceeded national standard," Mr Jones said.
The 24-hour standard for PM10 particles (which includes dust) is 50 millionths of a gram per cubic metre. The day-averaged indicative data for Launceston for the 12th was just over 40 millionths of a gram per cubic metre, and for Hobart was just over 20 millionths of a gram per cubic metre.
"This suggests that the air quality standard was not breached in either city, but a definitive statement cannot be made until the validated reference data become available in around six weeks time," Mr Jones said.
The hourly-averaged peak signal in Launceston on the evening of the 12th was near 120 millionths of a gram per cubic metre.