Updates to our Terms of Use

We are updating our Terms of Use. Please carefully review the updated Terms before proceeding to our website.

Thursday, July 18, 2024 | Back issues
Courthouse News Service Courthouse News Service

Particulate matter from over a decade of wildfires caused over 52,000 premature deaths in California, new study estimates

Using a model that compared California Department of Public Health mortality data from 2008 to 2018 with records of particulate matter concentrations caused by wildfires, researchers estimated that between 52,480 and 55,710 premature deaths were caused by particulate matter from wildfire smoke.

(CN) — It’s not only the flames themselves that have killed people, destroyed communities, and ravaged wilderness areas when huge wildfires have wreaked havoc in California. The tiny particulate matter their smoke leaves behind has also caused over 52,000 premature deaths, according to a new study.  

Published in Science Advances on Friday, the study details how researchers developed a new epidemiological model that compared California Department of Public Health mortality data from 2008 to 2018 with records of particulate matter called PM2.5 concentrations caused by fires. 

Using that data, the researchers estimated that particulate matter specifically from wildfires caused between 52,480 and 55,710 premature deaths between 2008 and 2018. 

“It’s just a major issue at the climate health nexus,” and a public health issue, said Rachel Connolly, the project director at UCLA’s Luskin Center for Innovation in the environmental health sciences department, and researcher at UCLA’s Fielding School of Public Health. Connolly is the lead author of the study. 

Wildfires produce a particularly toxic particulate matter that can be up to 10 times more harmful to people than other sources of air pollution, especially people’s respiratory health, which can affect people’s long-term cardiovascular and respiratory health, causing illness, hospitalizations and premature death, the researchers write in their study. 

Premature deaths from particulate matter from wildfire smoke accounted for 19% of all deaths attributed to all sources of PM2.5  pollution in California from 2008 to 2018, the researchers say.  

With climate change encroaching human development into nature — places referred to as wildland-urban interface areas — and what the authors of the study refer to as “questionable wildfire management practices emphasizing fire suppression” and California’s longer wildfire season, the chances of wildfires spreading that toxic smoke around have all increased, the researchers write in their study.    

Particulate matter from smoke is a problem for people living near areas where wildfires erupt, but it isn’t just a problem for rural parts of California where a lot of wildfires start. People in urban areas in L.A., the Bay, and the San Joaquin Valley can get sick as well because the smoke from distant fires travels, the researchers write.

The Environmental Protection Agency uses a cost-benefit analysis called a “mortality risk valuation” to estimate how much people are willing to pay for “small reductions in their risks of dying from adverse health conditions that may be caused by environmental pollution.”  

The researchers estimated that when it comes to risk from wildfire-caused pollution, Californians have an economic valuation of $432 to $456 billion.

“The large, growing impacts of wildfires on air pollution along with the mortality and economic burden presented here raise questions about societal investments in wildfire prevention and management. The state and federal governments have committed to a multiyear increase of about $6.7 billion for wildfire mitigation, but such investments fall well below the projected cost savings if greater investments were made to prevent and manage wildfire impacts,” the researchers write in their study. 

More studies have to be done on air pollution modeling to offer more precise health impact assessments of wildfire concentrations, including using machine learning analysis to isolate pollution from wildfires, and how to cultivate “community resilience and protecting vulnerable populations, who have less access to wildfire mitigation resources and reduced adaptive capacity,” the researchers write.

Connolly and her colleagues' study should be taken as “a call to invest in forest management and climate change action,” she said. “This is really important and affects the long-term health of people.”

Categories / Environment, Regional, Science, Weather

Subscribe to Closing Arguments

Sign up for new weekly newsletter Closing Arguments to get the latest about ongoing trials, major litigation and hot cases and rulings in courthouses around the U.S. and the world.