During the southern summer period, south-western Australia and the Sydney area are affected by large-scale bushfires with more than 3 million hectares burned. Due to the extreme heat at this time of year, the fires in December 2019 were particularly large and spectacular. Sydney's streets, residential areas and business districts were affected by smoke from the fires. The air pollution is not without short-term and long-term risks to the health of residents.
What are the risks for people exposed to fire fumes?
These fires produce unprecedented ambient air pollution and air quality is severely degraded by the presence of fine soot particles at particularly high levels.
According to the WHO, this pollution poses a high risk to the health of the population.
During this episode of high intensity air pollution, health services and hospitals in the areas affected by the smoke have seen an increase in their activities to treat eye and respiratory system irritations.
Fine PM10 particles less than 10 µm (1000 µm = 1 mm) in diameter penetrate the upper respiratory tract, and fine particles less than 2.5 µm (PM2.5) in diameter will penetrate deep into the lungs and into the alveoli of the lungs.
The fine particles in the fumes cause severe irritation of the respiratory tract (nose, throat, lungs).
Their presence in the respiratory tract causes significant irritation of the mucous membranes, an increase and aggravation of asthma. The WHO recommends the following guide values as a health risk threshold for exposure to fine particles :
- PM2.5: 10 μg/m3 as annual average and 25 μg/m3 as daily average
- PM10: 20 μg/m3 as an annual average and 50 μg/m3 as a daily average
In the case of the Australian fires of December 2019, at the height of the pollution episode, the official values for these parameters reached several hundred µg/m3.
During the fires, air pollution reached unprecedented levels
Is fire smoke pollution persistent?
Soot and fine particles settle and accumulate in the interior of buildings. They are loaded with combustion products that are carcinogenic to humans: Polycyclic Aromatic Hydrocarbons (PAHs).
PAHs are very stable in the indoor environment of buildings and their presence persists for many years.
These chemical molecules are very stable and persistent in the environment, especially in indoor air. Since we spend so much of our time indoors, it is essential to protect ourselves from chronic exposure to these toxics.
How to measure indoor air pollution from fires?
PAHs are the main markers of fires. They are low volatile, i.e. they are fixed to dust particles. Thus, an analysis of the dust can be used to determine the level of pollution and assess the health risks. In the case of bush fires in Australia, it is advisable to carry out this analysis to find out the level of exposure.
Exposure to fire pollution is a health hazard.
The YOOTEST Pollution Fire kit has been specially designed to measure indoor air pollution by PAHs. Dust sampling is very easy to carry out with the filter supplied and a vacuum cleaner. The dust sample is then analysed in the laboratory by indoor air pollution experts and the results are presented and interpreted in a comprehensive report.
A laboratory dust analysis measures the level of pollution in a house, apartment or office.
The average pollution levels found in dwellings are in the range of 0.1 to 10 µg/g (microgram PAHs per gram of dust). In case of proven pollution of the indoor environment by PAHs, urgent action is needed to limit daily exposure.
How can you prevent your exposure to fire pollution?
At the first signs of outdoor air pollution, it is strongly recommended to wear a mask filtering out fine particles to protect against the effects of acute exposure. To preserve the indoor environment of buildings, ventilation should be kept to a minimum until the situation returns to normal.
In case of indoor air pollution, it is essential to act as soon as possible to improve indoor air quality.
To limit pollution of the indoor environment, it is important to eliminate the source of pollution (thorough cleaning), to ventilate when outdoor air pollution levels have returned to acceptable levels, and to treat the indoor air using a device incorporating a HEPA particle filter to remove dust.
Dust analysis is used to monitor the effectiveness of cleaning and indoor air treatment devices.
A dust analysis makes it possible to ensure that the actions put in place to eliminate fire pollution have been effective.
Which regions are affected by bush fire pollution?
Smoke laden with fine particles has polluted a very large area and exposure to fire pollution now affects several million people in Australia. A state of emergency has been declared for the New South Wales region due to the extreme temperatures associated with the bush fires.
According to the authorities, the main areas affected by bush fire smoke are : Central Queensland, South Eastern Queensland, New South Wales (North Coast, Mid North Coast, Cessnock, the Hunter Region, the Hawkesbury north west of Sydney, the Wollondilly south west of Sydney, the Blue Mountains west of Sydney and the South Coast. On 20 December, serious fires took hold in South Australia, especially in the Cudlee Creek area of the Adelaide hills.
If you live or work there, a preventive analysis of household dust pollution is strongly recommended.