What did we find from air quality testing?
After the fires
The air samples collected between 5 March and 3 April 2014 showed that all substances from that round of testing were within the relevant guidelines for the protection of human health and the environment.
During the fires
PM2.5 levels were very high on occasions, particularly in the two weeks following the outbreak of the fire. The PM2.5 guideline was exceeded on 21 days at the monitoring station at Morwell South, and on 13 days at Morwell east. The PM10 guideline was exceeded on three days at Traralgon and eight days at Morwell south.
Carbon monoxide (CO) levels were also recorded at high levels at particular times. There were three occasions when the CO standard was exceeded (21, 22, 26 February 2014). As the fire became more contained, the CO levels dropped significantly, and from 27 February 2014 onward, the CO levels have met the standard.
The visibility reduction (VR) measurements were very high for a significant period of the fire event, with levels exceeding acceptable visibility even four weeks after the onset of the fire.
As with bushfires and planned burns, this mine fire produced copious amounts of smoke with similar VR properties, but the main difference was that it lasted a long time and was very close to a large population.
The sulfur dioxide (SO2) monitoring showed lower levels than anticipated from a coal fire of this scale. No significant SO2 levels were detected in Morwell or Traralgon. The peaks that were detected were not considered to be very high and fitted within the range of what would be expected from normal power station emissions. No standards were exceeded.
All other compounds measured were compared against a range of Australian and international criteria. With the exception of benzene, none was ever at a level that exceeded these criteria. Benzene levels marginally exceeded the standard on two occasions – once on 26 February 2014 and once on 27 February 2014.
Please visit the Department of Health and Human Services website for more detailed information on these results for benzene.
How does EPA assess its measurements?
The values of the various air contaminants are compared to standards and guidelines in order to assess whether they are of concern or not.
The EPA is responsible for protecting the general environment, therefore the standards used are for ambient environmental conditions. These are set down in Australian legislation, and are consistent with best international practice. They are almost all set at levels to protect the health of the most sensitive members of the population (young children, people over 65 and those with respiratory and heart conditions).
Are there long-term health effects?
A long-term study is being undertaken to ensure that any health effects from the mine fire are identified.
More information on the long-term health study is available from the Hazelwood health study website.
Is EPA still monitoring air quality?
EPA continues to monitor and reports on air quality at five sites in the Latrobe Valley: Moe, Churchill, Morwell east, Morwell south and Traralgon.
Up-to-date air quality data from the Latrobe Valley air monitoring stations can be seen at EPA AirWatch.