Air, soil, water and dust: New study focuses on long-term health impacts of LA wildfire pollution

A team of university researchers has launched a planned 10-year project to examine pollution from Los Angeles' recent wildfires and study its long-term impacts on health.

The researchers, including those from UCLA’s Fielding School of Public Health, say they want to look at what exposure to pollution from thousands of burned structures does to people over time.

Specifically, they say, they’ll look at how Angelenos’ respiratory, neurological, cardiovascular, immune and reproductive systems may be affected.

Although the project is expected to go on for years, some answers may be available much sooner.

"We are committed to sharing this information quickly," said Joe Allen, associate professor at Harvard T.H. Chan School of Public Health, one of several participating universities.

"This is not going to be a case where we collect data, sit on it and publish it in academic journals,” he said. “ The first priority is to get data out to people."

Initial findings will be available on a website (coming soon) and shared with public health officials later this month.

Why now?

The Palisades and Eaton fires that ignited Jan. 7 killed 29 people and destroyed more than 16,000 structures.

They also exposed millions of residents to hazardous smoke and debris.

Now that the fires have stopped burning, the team behind the Los Angeles Fire Human Exposure and Long-Term Health Study, or L.A. Fire HEALTH Study, is rushing to analyze outdoor and indoor air samples to help guide safe reentry and cleanup procedures.

“If we don't supply the science quickly, we could have large numbers of people going back into their homes that haven't been properly remediated and exposing themselves to unacceptably high levels of volatile organic compounds, which could have immediate and long term health consequences,” said Michael Jerrett, a professor at UCLA’s Department of Environmental Health Sciences.

Public health officials have warned L.A. County residents about serious health risks in burned areas and even miles away, but little is known about exactly which pollutants are present, at what levels, and where.

Testing air, soil, water and dust

The study aims to change that by testing the air, soil, water and dust in and around people's homes. The effort is a collaboration led by experts from Harvard, UCLA, UC Davis and the University of Texas.

Researchers say they have established 15 monitoring locations throughout Los Angeles County to track pollution levels over time, with a focus on helping residents understand when it's safe to return home.

They’re also sending vans equipped with advanced instruments (including mass spectrometers) through affected neighborhoods to measure the chemical composition of particulate matter and gases on each block in real time.

And they’re collecting much more detailed data than the standard air quality sensors used to calculate the Air Quality Index, or AQI. Those standard sensors measure how many tiny particles are in the air, but this study aims to determine exactly which pollutants are present in those particles, and at what amounts.

Risks linger in the air

In the days after the fires started, Caltech scientists found massive spikes in lead and other toxic chemicals in the air at a monitoring site in Pico Rivera — more than 10 miles from the Eaton Fire.

Unlike forest fires, urban wildfires create a uniquely dangerous mixture of pollutants because of what’s been burning: buildings, vehicles and manufactured products that all contain toxic chemicals.

Researchers are tracking particulate matter, gases, chemicals, heavy metals, asbestos, PFAS (so-called “forever chemicals”), microplastics and other toxic pollutants. The particles can settle into soil and dust, potentially becoming re-suspended during cleanup and rebuilding efforts.

"We're already seeing from the early data that the mix of pollutants from this urban wildfire are different from the types of pollutants we see when it's just a wildland fire," Allen said.

That means these fires have the potential to cause far greater health risks than standard vegetation-fueled wildfires.

“We know it impacts brain health, lung health and heart health,” said Allen. “But the L.A. fires give us an opportunity to not only help the population that's impacted, but to really understand what the health impacts are of a wildfire like this in a dense urban environment where we know the mix of pollutants are different.”

The study is also using advanced machine learning to model and predict how wildfire smoke may have penetrated 14 million homes across the L.A. region. "We're modeling every home in Los Angeles to understand how much smoke and pollutants might have infiltrated into the home," Allen said.

Researchers say they hope the analysis will help public health officials and residents understand which neighborhoods and types of buildings might have trapped more toxic materials, and require additional cleanup.

“That's going to give people some reassurance that at certain distances and certain locations away from the fire, they'll be able to go back to their homes,” Jerrett said.

The researchers are particularly focused on understanding how long hazardous compounds might continue to be released gradually from soft and porous materials, like furniture and carpets, that absorbed smoke during the fires.

Building long-term understanding

The study aims to make new discoveries about chronic diseases and conditions that might be triggered or exacerbated by exposure to urban wildfire smoke.

The findings could be useful as climate change boosts the likelihood of similar wildfires in the future, researchers said.

"The new normal is that we are going to experience more mega wildfires," said Jerrett. "What we don't have a very good understanding of at all is what the long-term implications are for this level of smoke exposure."