LOS ANGELES – Pollution from California's wildfires has killed more than 52,000 people in a decade, a new study found June 7. The western United States is bracing for a hot summer that could bring more fires.

In California and other parts of the country, huge areas of forest and grassland are burned every year, causing millions of dollars in destruction and sometimes losing human lives.

However, researchers say the particles released by the fires are having a devastating impact on the local population, far exceeding the number of deaths directly attributable to them.

A study led by Dr. Rachel Connolly of the University of California, Los Angeles, found that these tiny air pollutants – known as PM2.5 because they are 2.5 micrometers or smaller – are killing large numbers of people.

The team examined data from 2008 to 2018 and isolated the amount of PM2.5 released specifically by wildfires, as opposed to the amount generated by other sources such as transportation and manufacturing.

They found that at least 52,480 premature deaths were caused by this particular pollution. The cost of treating those affected by the pollutants was estimated at US$432 billion (Singapore dollars 584 billion).

“The importance of wildfire suppression will only increase in the coming decades as drying due to climate change intensifies and more regions become vulnerable to fire,” the researchers wrote in their paper, published June 7 in Science Advances, a peer-reviewed journal of the American Association for the Advancement of Science.

“These findings have direct implications for California, a state that is at the forefront of climate policy development, has many fire-prone regions, and has a diverse population that needs to be protected,” they added.

“It is critical to expand the evidence on the health impacts of wildfires and other climate-related stressors.”

The study comes at a time when large parts of California and the American West are suffering from the first heat wave of the year.

On June 6, temperatures in Death Valley reached up to 49 degrees Celsius, while Las Vegas reached 43.9 degrees Celsius.

The heatwave in early summer has raised concerns that 2024 could see severe wildfire seasons after two relatively mild years due to wet winters.