Pollution caused by California fires killed 52,000 people in a decade, study finds

Pollution from California wildfires has killed more than 52,000 people in a decade, a study reported Friday, as the western United States expects a hot, fire-prone summer. Researchers have established that pollution from fires has a devastating effect on local populations, far exceeding the number of deaths directly attributable to these fires.

This study, led by Rachel Connolly of the University of California, Los Angeles, focused on the impact of fine particles (PM2.5, 2.5 micrometers or less) released by wildfires between 2008 and 2018 , by ruling out other sources of pollution such as transport or industry. According to their results, at least 52,480 premature deaths can be attributed to fires in California over ten years. The team of researchers also estimated the total cost of care for infected people at $432 billion.

Worrying heat wave

“The importance of wildfire management will only increase in the coming decades as aridification intensifies with climate change and more and more regions are exposed to fire”the researchers said in the study published in Science Advances. “These findings have direct implications for California, a state at the forefront of climate policy development with several fire-prone regions”, they added. Large areas of forests and grasslands burn every year in California and other parts of the country, causing millions of dollars in damage and sometimes resulting in multiple deaths.

The study comes as an early heat wave hits the western United States. Las Vegas sweltered in 44 degrees Celsius on Thursday while the desert region of Death Valley reached 49°C. These temperatures raise fears of a very intense fire season in 2024, after two relatively spare years, thanks to rainy winters. After about 20 years of drought and an increasingly arid climate, California has seen an alarming number of megafires this century, with 18 of the state’s 20 largest measured fires occurring in the last two decades.