Science & Technology, Australia (Commonwealth Union) – New research suggests that air conditioning not only cools the air but also plays a crucial role in reducing the risk of harm from bushfire smoke.
Recent findings indicate that workplace air conditioning not only provides a cooling effect but also effectively captures particles from bushfire smoke, thereby decreasing exposure to potentially hazardous elements like soluble mercury, sulfate, and nitrate. This discovery is particularly significant considering the health risks associated with bushfire smoke, including the potential to cause or worsen conditions such as asthma, chronic obstructive pulmonary disease (COPD), and heart disease, leading to an elevated risk of hospitalization and mortality.
The study, featured in the journal Environmental Pollution, was spearheaded by Raissa Gill, a PhD candidate in environmental science at the University of Technology Sydney (UTS) and a recipient of the UTS Research Excellence Scholarship. Collaborating with researchers from UTS and UNSW Sydney, Gill emphasized the substantial air pollution generated by the 2019–2020 ‘Black Summer’ bushfires in Australia. The extensive plumes of smoke from these fires traveled long distances, enveloping Sydney and its surrounding areas.
She indicated that they aimed to delve deeper into the composition of the bushfire smoke they were inhaling. Utilizing commercial air conditioning filters enabled them to capture and examine the chemical makeup of particles that would have otherwise been breathed in.
The scientists gathered particulate matter from HVAC filters in UTS Buildings 4 and 7, both during the peak of the Black Summer bushfires and one year later for comparison.
They observed that daily concentrations of particulate matter were generally 2–3 times higher than usual, with hourly concentrations spiking up to 10.5 times the normal maximum. This surpassed national standards on 19% of days within the four-month sampling period. Additionally, the particles exhibited finer characteristics and contained a distinct blend of toxic chemicals.
According to UTS Professor Martina Doblin, a co-author of the study, bushfire aerosols featured smaller, rounder particles compared to urban aerosols. This composition increases the likelihood of inhalation into the lungs and the transfer of toxic elements into the bloodstream.
“These particles also contained more soluble forms of mercury, as well as higher concentrations of sulfate, nitrate and fluoride ions and metals including manganese, cobalt, and antimony. Mercury is quite toxic even in low concentrations and can cause neurological problems and lung damage.”
The research underscores the varied chemical transformations induced by severe bushfire occurrences in the atmosphere. Comprehending these alterations is essential for evaluating the impact of bushfires and their potential repercussions on human health and environmental well-being, according to the researchers of the study.
UTS Associate Professor Fraser Torpy, a co-author of the study, emphasized the significance of this understanding. He stated, “Although Sydney generally maintains good air quality on a global scale, recent evidence unmistakably reveals that a few days each year characterized by elevated pollution levels from bushfires and dust storms contribute significantly to diseases and fatalities within the community.”
Professor Torpy stressed the crucial role of studies that enhance our comprehension of these heightened pollution events. He emphasized, that such investigations are vital in discerning the root causes of these health crises and will contribute to a more profound understanding of how we can safeguard vulnerable community members.
Although HVAC systems aren’t explicitly tailored for handling bushfire smoke, a study on indoor air quality in Canberra during the 2019-2020 fires revealed that outdoor levels of fine particulate matter were found to be up to 10 times higher than the measured values indoors with air conditioning.
“Given that severe bushfires are projected to increase with climate change, the role of bushfire-ready infrastructure in maintaining public health, as well as the need to reduce greenhouse gas emissions, is now more pressing than ever,” Gill explained.
