'Hazardous' air quality from bushfire smoke triggers spike in hospital admissions

The blanket of smoke covering kilometres of Queensland and New South Wales as a result of prolonged bushfires has seen a spike in emergency department presentations for respiratory problems, but illnesses such as heart attack and stroke are also likely to be triggered from the ongoing air pollution.

According to the World Health Organisation, an estimated 4.2 million premature deaths globally are linked to ambient air pollution. One of the pollutants most strongly associated with air pollution is particulate matter, extremely small solid particles and liquid droplets suspended in air. During bushfires, particle pollution can reach high concentrations.

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While Australia’s national standard is less than 8 micrograms/m³ of ultrafine particles, suburbs 25km or more away from the fires have reached 50 micrograms/m³ in recent days. By comparison Jakarta, which frequently ranks among those cities with the most dangerous levels of air pollution, maintains particulate matter levels upwards of 140 micrograms/m³.

But Australia’s elevated concentrations from fires are enough to affect people with existing respiratory, heart and neurological conditions. According to the NSW department of health, short-term exposure to particulate matter appears to exacerbate pre-existing diseases while long-term exposure most likely causes disease and increases disease progression. Particles with a diameter of 2.5 micrometres are the most problematic, so small they can get deep into the lungs and into the bloodstream.

Dr Arnagretta Hunter, a cardiologist with Doctors for the Environment Australia, said the smoke smothering parts of Australia was most dangerous for those with preexisting conditions such as asthma or heart disease.

“The way I think about it, it’s a bit like cigarettes,” she said. “Smoking a cigarette if you have been smoking a long time can trigger a heart attack, but it doesn’t always. It can be the fumes from motor vehicles that trigger an attack, and we know living near arterial roads is associated with heart disease.

“The challenge with this fire season is the number of people exposed to bushfire smoke in some regions is greater than we’ve seen before. It is putting us through new experiences in terms of the health consequences.”

The vice president of the Australian Medical Association, Dr Chris Zappala, said healthy people probably did not need to worry too much. But he urged those with any chronic health conditions such as asthma to take extra precautions, and not to hesitate to call an ambulance or go to an emergency department if they were worried.

“They should try as much as possible to limit exposure by staying inside and increasing preventer medications which need to be taken every day usually and then also relievers for immediate symptom control,” Zappala, who is a respiratory physician, said. “They will need to carry those medications with them, and anyone with a chronic lung condition however mild must act preemptively.”

For other people, the haze is unlikely to have long-term ill effects.

“It will be mildly irritating,” he said. “It will cause coughing but not long-term injury. Our airway is designed to filter and deal with a whole range of dust particles and spores and it does that very effectively on a day-to-day basis, and those filtering and cleaning mechanisms will take care of it even if the smoke goes for several days.”

While people should try to avoid being outside, he said they should not necessarily avoid exercise outside, or activities such as cycling or walking to work because the benefits of those outweighed the irritant from the smoke.

The Australasian College for Emergency Medicine [Acem], the Royal Australasian College of Physicians, the Climate and Health Alliance and the Australian College of Rural and Remote Medicine President have all declared climate change a medical emergency in recent weeks.

Acem president Dr John Bonning said bushfires and heatwaves lead to surges in presentations to hospital emergency departments and that patients with histories of conditions like asthma, emphysema and allergies, as well as pre-existing cardiac conditions were most at risk.

“Heatwaves can also lead to increased presentations for conditions such as heatstroke, cardiac events and mental health issues,” he said. “This disproportionately affects some of our most vulnerable patients, including the elderly and children. It is also an equity issue, as people without insulated homes, or who are unable to afford air conditioning, are at increased risk.”

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Associate professor Linda Selvey from the University of Queensland’s school of public health said the government must develop a national climate change and health strategy.

“I know that health departments are aware of and talking about the issue, but in terms of overall climate change adaptation and strategy, we are way behind where we need to be,” she said.

Climate and Health Alliance executive director Fiona Armstrong said the bushfires being seen in Australia were “not normal”. With Victoria reaching 39C on Thursday and experiencing extreme winds and a code red warning, potential for bushfires, and a risk of a thunderstorm asthma event, she said people should stay indoors and follow medical advice to avoid putting themselves at risk.

“The conditions we are experiencing are those that scientists have warned about for decades,” Armstrong said.

“Without decisive action to phase out the burning coal and other fossil fuels, the main cause of global warming, these conditions will continue to worsen.”