For the past several months, hundreds of bushfires near Sydney and across New South Wales have been devastating the area and choking Australian residents. As of January 8, they have destroyed over 10 million hectares of land, burned down more than 5,900 buildings, and claimed the lives of 28 people.
In parts of Sydney and NSW, smoke from the bushfires has created air pollution that is up to 11 times greater than the base “hazardous” level for air pollution, and the Climate and Health Alliance (CHA) has declared air pollution in NSW a public health emergency. In a joint statement with over 20 medical groups representing 25,000 doctors and trainees, the CHA called on the government to act urgently to reduce greenhouse gas emissions, specifying that climate change is making weather events more extreme, including bushfires, which are having “devastating impacts on human health”.
Why are bushfires harmful to our health?
What makes bushfires particularly hazardous to our health is the fine particles they emit, specifically particulate matter (PM). Ambient particulate matter is a collection of tiny solid or liquid particles that can remain suspended in the air and be transported by wind. Scientifically speaking, ambient particulate matter pollution refers to outdoor air concentrations of particulate matter where particles are up to 2.5 micrometres in diameter. Larger-sized particulate matter (particles with a diameter of 10 micrometres or larger) can sometimes be seen by the naked eye when present in higher concentrations, however the smaller particulate matter, such as PM2.5, can only be seen under a microscope.
These smaller particles, known as fine particulate matter, or fine particles, have raised the most concern as they are able to burrow deep into our bodies, get lodged in our lungs, and even enter our bloodstream. Short-term effects of PM2.5 may include irritation of the eyes, nose, throat and/or lungs, sneezing, coughing, shortness of breath, and worsening of asthma. The gradual, long-term exposure can be far more serious, and is known to contribute to stroke, ischemic heart disease, chronic respiratory diseases, lower respiratory infections, tracheal, bronchial and lung cancers, as well as premature births and low birthweight babies.
Some groups are more sensitive to particulate matter pollution. These include newborns and young children, pregnant women, older adults, and individuals with cardiovascular or chronic respiratory illnesses, obesity or diabetes.
What else causes ambient particulate matter pollution?
Ambient particulate matter can be emitted from industries and powerplants that burn fossil fuels, homes that burn firewood, and motor vehicles such as cars, buses, and trucks that use gas or diesel. Particulate matter also occurs naturally from non-human activities, such as volcanic eruptions, forest fires or bushfires, dust storms and tornadoes, and can be moved around by wind.
What level of particulate matter is considered “safe”?
There is no safe level of particulate matter pollution, and the greater the levels, the more hazardous the effects on health. The World Health Organization (WHO) recommends that the annual average PM2.5 concentrations do not exceed 10 micrograms per cubic meter, and that 24-hour average concentrations do not exceed 25 micrograms per cubic meter.
How can you reduce your exposure to particulate matter?
To help reduce overall particulate matter, governments and policy makers can mandate reductions to overall emissions and take action on climate change, which is exacerbating extreme weather events, including those that produce particulate matter pollution.
However, there are many steps you can take as an individual to help improve the air you breathe:
- Use an air quality monitor in your home to track particulate matter pollution and other changes in air quality. Many consumer-grade, easy-to-use monitors are available online.
- Use a high-efficiency particulate matter (HEPA) filter. They absorb at least 99.97% of particulate matter and are one of the best choices you can make when trying to reduce your PM exposure.
- Stay informed about levels of outdoor particulate matter pollution in your area.
- If the outdoor air quality is poor, keep your windows, doors, and the fresh-air intake of the AC unit closed.
- Consider a vacuum cleaner with a HEPA filter, which is designed to filter at least 99.97% of particles larger than 0.3-microns in diameter. This is especially important when cleaning your home after wildfires, as HEPA filter-equipped vacuums (as well as damp mopping and dusting) can help reduce the re-suspension of particles that have settled in your home.
- Wear an air pollution mask or particulate respirator if you live in or travel to areas with high levels of PM to help keep particles from getting into your system.
- Limit candle burning (both regular and scented) in your home, or switch to electric ones. If you can’t limit candle burning, use an air filter, or at the very least open a window, especially when blowing the candles out.
- Use public transit. Vehicles are one of the main sources of particulate matter pollution, so less cars on the road can help tackle the root of the problem.
- If you rely on your own vehicle, consider making a switch to a hybrid or electric car. This can help reduce particulate matter emissions, to the benefit of your health as well as those around you.
About the Author
Regina is an expert on the relationship between the built environment and human health. At Delos, her research focuses on the role that various environmental and behavioral factors play in physical and mental health and well-being, including air and water quality, lighting, material composition, diet, sleep, and physical activity, among others. Regina’s work informs the evaluation, development and delivery of products and services for commercial, residential and hospitality sectors.
Regina holds an MSc of Human Nutrition from Columbia University. Her thesis research on prenatal diets and maternal and child health outcomes served as a basis for a book on these topics. Prior to her graduate studies, she worked on a nationwide study at the Research Foundation for SUNY, examining information processing among individuals with a family history of addiction. She earned her Bachelor of Biology at Bard College, where she was a Distinguished Scientist Scholar. Regina’s work has been published in several peer-reviewed journals and conference proceedings.
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