Bushfire smoke causes measurable eye damage, study shows
New research has revealed that bushfire smoke can cause measurable damage to the eye surface of firefighters on the front line.
Published on the 15 July 2025 by Kate Burke
During the height of the Black Summer bushfires, Sydney optometrist Dr Sukanya Jaiswal noticed a troubling trend.
“There was a sudden increase in patients having eye problems. They were coming in with red, very irritated eyes, even with soot particles embedded onto the front surface of their eye,” she recalls.
“It continued happening consistently throughout November and December 2019, and I realised there wasn’t a lot of information or guidance available on how to manage these issues, especially because we didn’t know long the air quality would remain poor,” says Dr Jaiswal, from the UNSW School of Optometry and Vision Science.
That experience sparked a research journey that led to the first field study investigating how bushfire smoke affects firefighters’ eye health.
“Talking to firefighters revealed that despite advances in protective equipment, bushfire smoke exposure continues to cause significant eye irritation, and there are concerns about lasting damage,” says Dr Jaiswal.
The study, published in the International Journal of Environmental Health Research, found even short-term exposure to smoke led to increased eye discomfort, dryness and irritation for firefighters.
Researchers also observed clinical signs consistent with eye surface damage, including reduced tear film stability and increased staining of the cornea and conjunctiva – the mucous membrane that covers the front of the eye and lines the inside of the eyelids. Soot particles were also found in the eyelids and tears of several firefighters.
“It was surprising to see just how much soot clung to the skin around the eyes and on lashes after a shift,” says Dr Jaiswal. “Once it’s there, it’s easy for particles to fall into the eye or be rubbed in, which can lead to further irritation and damage.”
Testing on the fireground
UNSW Researchers recruited 23 firefighters, aged between 19 and 60, to assess eye symptoms and clinical signs of eye surface damage before and after four prescribed, or controlled, burns conducted by the NSW National Parks and Wildlife Service between August 2023 and May 2024.
A subset of participants wore personal air monitors to measure exposure to fine particulate matter (PM2.5), with recorded levels ranging from 130 to 480 micrograms per cubic metre, comparable to those seen in major bushfire events.
Examinations assessed symptoms such as dryness, discomfort and foreign body sensation, as well as tear film stability and conjunctival redness.
Tear film protects the ocular surface and is crucial for maintaining clear vision and eye comfort, explains study co-author Professor Isabelle Jalbert, also from the School of Optometry and Vision Science. “When our tear film is damaged, it can become unstable and evaporate more quickly, which can lead to consequences like blurry vision and stinging.”
An attempt was made to collect tear samples from the firefighters, but only six were suitable for analysis due to low tear volume and technical issues caused by environmental factors like wind, dust and low humidity. Although no significant change in the inflammatory marker IL-1β was detected post-burn, baseline levels were higher than expected, suggesting possible residual inflammation from prior smoke exposure.
“It’s well established that bushfire smoke causes an inflammatory reaction in the airways, so we were anticipating these signs of inflammation on the eye surface,” Prof. Jalbert says.
The study was not designed to detect long-term effects but provides evidence that smoke exposure can affect eye health in ways that have gone unrecognised.
Eye protection gaps
The study also examined protective eyewear use and recovery measures. Most firefighters wore protection for at least some of the time, but only seven (30%) used sealed goggles for at least half of their shift, while 13 (56%) wore sunglasses and four (17%) wore no protection. Some (39%) rinsed their eyes or used drops during or after their shift, but this was not routine.
Professor Isabelle Jalbert assesses the eye of a NSW National Parks and Wildlife Service firefighter after a controlled burn.
Photo: Sukanya Jaiswal/UNSW
The findings confirm what researchers heard when they surveyed 338 bush firefighters from seven organisations across NSW, Victoria and South Australia.
The survey found 55% of firefighters removed eyewear always or often due to sweat, fogging or other reasons, with some even needing to close their eyes while on the fireground to relieve smoke-induced irritation, according to findings published in the journal The Ocular Surface last year. Even those wearing goggles, could be exposed to particles due to side vents designed to reduce fogging.
"It's concerning that the severity of eye symptoms can be so significant that it causes firefighters to close their eyes or stop in their tracks, which they described as a hazard that can affect safety and operational capability,” Dr Jaiswal says.
The survey found 54% of firefighters always or often experienced eye irritation at work, and 30% frequently had irritation after work. Almost half (47%) worried about the long-term effect, but only 17% had sought healthcare advice.
Next steps: recognition, research and reform
The researchers say there is an urgent need to develop and confirm what strategies might best protect the eye surface, and to actively treat smoke-induced damage in firefighters. Non-goggle-based protection should be among the options explored, like using eyedrops before and after smoke exposure.
“We want recognition that eye exposure to smoke is a serious issue,” says Prof. Jalbert. “Now that we understand the physiological impact, the next step is to ensure its acknowledged and addressed.”
The pair is now investigating better ways to manage the impact of smoke on the eye health of firefighters, with support from Natural Hazards Research Australia, to develop new guidelines and recommendations to reduce the risk of eye damage.
Further research is needed to understand the long-term impact of repeated smoke exposure on eye health, not just for firefighters, the researchers say. Public health guidelines also need to be updated to reflect the damage that can be caused to the general community during large bushfire events.
“Protecting the eye surface is critical not only for firefighters, but for the wider community increasingly exposed to bushfire smoke,” says Dr Jaiswal.
“There’s growing recognition among fire agencies that eye symptoms are common in the workforce, and we’ve seen great support and interest from agencies in this research, but the issue is not yet well acknowledged in broader public health guidance,” she adds. “We need greater awareness that these symptoms can indicate real damage to the eye’s surface and to ensure that people know when to seek professional care.”
The research was supported by a postgraduate scholarship awarded by Natural Hazards Research Australia and a UNSW Postgraduate Award to Dr Jaiswal.
Dr Sukanya Jaiswal with one of the 23 firefighters assessed for clinical signs of eye surface damage.
Photo: Ali Alghamdi UNSW
Media enquiries
For enquiries about this story and interview requests, please contact Kate Burke, News & Content Coordinator, UNSW Medicine & Health.
Tel: +61 2 9348 2538
Email: kate.burke@unsw.edu.au
