Exposure to bushfire smoke worsens heart and lung conditions and raises big health questions, say Newcastle researchers who examined the Black Summer fires.
A Hunter Medical Research Institute [HMRI] team found that PM10 particle pollution from bushfires had a "significant effect on heart and lung function" - even over a short period.
These effects occurred "in the absence or presence of asthma".
A rise in hospitalisations for heart, lung and brain conditions was recorded during the Black Summer.
In Newcastle and Lake Macquarie, an 85 per cent increase in hospitalisations [46 in total] for cerebrovascular conditions, including stroke, occurred in the week from January 5, 2020.
And on the Central Coast, a 96 per cent increase in hospitalisations [42 in total] for heart attacks occurred in the week from December 1, 2019.
This happened during the notorious Wollemi megafire, known as the Gospers Mountain blaze, which burnt more than 500,000 hectares.
It set a record for being the biggest forest fire in Australian history and caused widespread hazardous air pollution.
Across NSW, there was a 7.6 per cent increase in hospitalisations [20 in total] for heart conditions in the week from January 19, 2020.
Professor Doan Ngo, of HMRI and University of Newcastle, said the heart health issues "coincided with the combination of the heat and bushfires".
"We don't know if it's directly related," Professor Ngo said, adding that they could have been linked to stress from the bushfires.
She said it was important not to "neglect the health effects of bushfires".
"The air pollution was prolonged," she said.
In the week from November 10, 2019, as fires burned, there was a 75 per cent rise in asthma hospitalisations for Newcastle and Lake Macquarie residents.
Across NSW, hospitalisations for asthma rose by 19 per cent in the week from December 29, 2019, and 25 per cent from the week of January 5, 2020.
Dr Henry Gomez, the study's lead author, said air pollution such as bushfire smoke raised "big questions for our health that need to be addressed".
He said the study, published in The Journal of Allergy and Clinical Immunology, involved analysis of "what in the particulates might be affecting our bodies".
"We know the particulates affect our airways," he said.
"The chemicals and elements that make up those particulates make their way into our bodies' circulation, which then affects organs such as our heart."
The research showed that "even healthy airways exposed to these bushfire particulates are affected in a similar way to the airways of asthmatics".
"Healthy airways exposed to these particulates contract more than they should."
When asthmatics were exposed to the particulates, their condition worsened and their steroid inhalers were less effective.
Professor Jay Horvat, who oversaw the study, said "even small amounts" of bushfire particulates had "significant effects on lung and heart physiology".
"New therapeutic strategies are required to protect people from the harmful effects of exposure, particularly for those at increased risk," he said.
"The prevalence and intensity of landscape fires is likely to increase globally as a result of climate change."
Heart and asthma foundations urge affected people to stay indoors, preferably in air-conditioning, and keep medicine close by when bushfire smoke is present.
Properly fitted N95 masks can protect against smoke and air pollution.
