November 18, 2022

Dr. Julia Rager

Dr. Julia Rager

A research team led by Julia Rager, PhD, assistant professor of environmental sciences and engineering at the UNC Gillings School of Global Public Health, has received more than $500,000 in funding from the Environmental Protection Agency’s (EPA) Science to Achieve Results (STAR) program to study toxic mixtures of chemicals in wildfire smoke.

“Wildfires are increasing in both prevalence and intensity worldwide — a disastrous scenario that is steadily becoming more common alongside global climate change,” Rager said. “This project will provide data that are currently rate-limiting in human health risk assessments of wildfire smoke exposures, while also addressing the need to improve mixtures toxicity test methods.”

The project aims to understand how individual chemicals in wildlife smoke induce responses in a lab setting that group according to biological pathways and inform mixtures-based joint toxicities that overlap with pulmonary responses and disease outcomes in people.

The award is part of $7.7M in STAR program research funding to 11 institutions to develop and evaluate innovative methods and approaches to inform human health risk assessment of environmental chemical mixtures.

The researchers will leverage existing chemical characterization results from variable biomass burn scenarios, representing wildfire events, to prioritize chemicals that co-occur in wildfire smoke to test for chemical groupings and joint toxicities. Lung cells from human donors will be exposed to individual chemicals, and transcriptomic signatures from exposed cells will be used to group chemicals. These chemical groups will then be tested using the same in vitro model, alongside the full chemical mixture and whole biomass smoke mixtures to compare individual chemicals, chemical groups and whole mixture effects on pathway-level responses.

“We will specifically combine in vitro and in silico new approach methodologies (NAMs) to efficiently test the variable landscape of exposure conditions that can result from wildfire smoke,” Rager said. “In vitro findings will be strengthened through comparisons against mouse and human data to result in improved mechanistic understanding and health risk quantifications on wildfires.”

Results from this study may help identify geographic locations and vulnerable populations at increased risk of the most harmful exposure conditions, based on biomass composition and burn scenarios.

Learn more about the award.

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