Current air quality measurements recorded at the EPA's monitoring stations around the State show that moderate to high smoke levels associated with the bushfires are being experienced at many locations. However, a number of these are significantly reduced compared with the extremely high levels recorded earlier this week, particularly at locations in the North and North West, and in the Huon Valley.
Smoke concentrations resulting from bushfire activity are difficult to predict and the levels may escalate again depending on the extent and intensity of the bushfires. Although smoke levels can vary rapidly according to wind movement, the current smoky conditions are expected to continue for at least a few days based on the prevailing wind patterns and forecast weather.
For bushfire information and alerts, visit the Tasmanian Fire Service website at www.fire.tas.gov.au
For information on smoke health risks and public health alerts, visit the Department of Health and Human Services website at Department's homepagewww.dhhs.tas.gov.au/publichealth/alerts
For information on air quality and real-time particle concentration data recorded at monitoring stations across the State, visit the EPA website at www.epa.tas.gov.au/epa/real-time-air-quality-data-for-tasmania
The interactive map provided on the EPA website presents the most recently available air quality data for smoke and dust particle concentrations monitored by the EPA at 29 locations across the State in a network known as BLANkET (Base-Line Air Network of EPA Tasmania). This data is used by the DHHS to assess the potential risk to public health and forms the basis for the public health alerts.
The smoke levels measured around the State over recent days represent both the highest levels and most prolonged smoke episode so far recorded by the EPA's BLANkET. The peak values of PM2.5 earlier this week were very high, with some instantaneous readings briefly over 2000 ug/m^3 at Wynyard, and up to 1000 ug/m^3 in the Tamar Valley. Some day-averaged PM2.5 values were also high, with a value over 500 ug/m3 at Wynyard, and, for example a day-averaged PM2.5 value for Launceston near 80 ug/m^3. The calendar-day national air quality standard for PM2.5 is 25 ug/m^3. Many stations have been recording calendar-day averaged PM2.5 above this standard.
In comparison, normal PM2.5 levels for this time of year, with no bushfires, would be around 2 to 5 µg/m3 due to natural background aerosols. As an approximate comparison, PM2.5 values below 5 µg/m^3 signify very clear air, while a smoky winter's evening might show levels near 50 µg/m3 for several hours or more than 100 µg/m3 on the worse nights.