New research by UCLA finds thousands more people than previously counted die each year in California due to the health impacts of wildfire smoke.

The research, published today in the journal Science Advances, finds that inhaling the fine particulate matter known as PM2.5 from wildland fires led to 52,500 to 55,700 deaths in the 11 years from 2008-2018, with an associated economic impact of $432 billion to $456 billion.

Lead author and UCLA researcher Rachel Connolly explains:

  • “Climate change, forest mismanagement and an expansion of the wildland-urban interface have led to worsening wildfires across California, and with those fires come smoke pollution and increasing health impacts from air pollution exposure. This is the first research exploring how that chronic, long-term smoke exposure affects people across the state.”
  • “Our numbers are higher than previous estimates because previous measurements considered the harms from short-term smoke exposure, but wildfire smoke is becoming an ongoing problem, and as a result, contributing to long-term disease formation.”
  • “A growing body of research suggests that particulate matter from wildfire smoke is more harmful to human health than particulate matter from other pollution sources. Society needs to invest in forest management and climate mitigation, both of which could yield significant health benefits.”
  • “Our study looked at California, using data from 2008-2018, but there have been several record-setting fire years since, both within and outside the state, which will also lead to significant health burdens. Like we saw with the Canadian fires last year and impacts on the East Coast of the U.S., massive fires can produce so much smoke that even regions that are not as fire-prone experience wildfire smoke exposures – and their populations are vulnerable to health impacts.”

Connolly is the project director for air quality and environmental equity research with the Luskin Center for Innovation at the UCLA Luskin School of Public Affairs, and a staff researcher in the Environmental Health Sciences department within the UCLA Fielding School of Public Health. The study’s senior author, UCLA environmental health expert Michael Jerrett, is a professor in the department of environmental health sciences at the UCLA Fielding School of Public Health, with expertise in environmental health effects of wildfire smoke and transportation-related pollution.

Media are encouraged to quote from Connolly’s comments, or reach out on these and other environmental topics for additional context, research and analysis from UCLA climate experts.

Alison Hewitt
Senior Media Relations Officer
UCLA Strategic Communications | Office of Media Relations | @ashewitt | @ahewitt.bsky