A personal smoke detector

Wildland firefighters spend their summers steeped in woodsmoke.

Whether they're working a 16-hour shift or sleeping in a tent at a fire camp, breathing smoky air is an occupational hazard linked to increased risk of lung cancer, leukemia, and other serious health problems.

To measure woodsmoke exposure, a Washington State University- led team has developed a low-cost, self-administered test for firefighters. It could be a game changer not only for the thousands of people who fight wildfires each year but others exposed to chronic smoke conditions or high doses over a short period of time.

Paper assay for measuring smoke biomarkers in urine; 3-D-printed attachment magnifies image on cellphone camera; app quantifies benzene metabolite levels. (Staff illustration based on ACS sourceworks and photos from Adobe Stock/Firefly)

The test allows people to monitor their smoke biomarkers in real time, says Annie Du, a research professor in WSU's School of Mechanical and Materials Engineering who is leading the project. The personalized results remove the uncertainty of estimating exposure based on regional air-quality monitoring.

People can inhale dangerous amounts of woodsmoke without showing symptoms, Du says. The amount of harm also varies by individual. Two firefighters working side by side can respond differently to the same smoke conditions. One might be OK, while the other firefighter's DNA is damaged.

"Some people's bodies will protect them from smoke exposure; others will be vulnerable," says Du, who also works in the College of Pharmacy and Pharmaceutical Sciences.

For those who are vulnerable, "we want to catch it early," she adds. "If you feel dizzy or nauseous, if your lungs hurt, if you need to go to the hospital, that's too late. You already have clinical symptoms."

Similar to pregnancy tests, the test requires a drop of urine on a paper assay. The researchers used tiny particles of platinum and palladium in the assay to improve the test's accuracy and sensitivity.

The test results aren't visible to the naked eye. But firefighters can use their smartphone cameras, a 3-D-printed attachment, and app to magnify the image and quantify the level of benzene metabolites in their urine.

Benzene, a pollutant found in woodsmoke, is associated with health risks including blood disorders, leukemia, and other cancers. After high-dose smoke exposures, benzene levels in the body can fluctuate quickly, which is why a rapid field test for firefighters is so important, Du says.

Blood tests can also be used to measure smoke biomarkers, but those samples must be sent to a lab for analysis, which is time- consuming and costly.

A grant from the US Centers for Disease Control and Prevention supports efforts to scale up the test for use in occupational settings. Besides the WSU team, researchers at University of Washington and University of Georgia contributed to the work.

Wildland firefighters in Georgia will help validate the test's accuracy this year, providing both blood and urine samples to compare measurements for their smoke biomarkers. WSU's Office of Commercialization is also providing funds to improve the test for future use in high-risk populations, including young children and the elderly.

Climate change has increased the frequency and intensity of wildfires, putting millions of people at risk each year from woodsmoke.

Someday, individual monitoring for smoke exposure may be as familiar to people as taking a COVID-19 test, Du says. And it will help safeguard the health of people working on the fire lines.

Based on their personalized test results, supervisors might need to rearrange some firefighters' shifts.

"Or they might need to take a break and come back next season," Du says. "Otherwise, that smoke exposure will damage their DNA and increase their risk of cancer."