As many as 3,000 people in California over the age of 65 have died between August 1 and September 10 because of the unprecedented smoke from the state’s record-breaking wildfires, according to researchers at Stanford University. The estimate — which other experts said was almost certainly lower than the actual number of excess deaths caused by wildfire smoke — dwarfs the 26 confirmed fatalities caused directly by the fires, and shows “the hidden cost of air pollution exposure,” Marshall Burke, an associate professor of earth system science at Stanford whose team estimated the impacts, told the San Francisco Chronicle. Burke also said California’s record-breaking extreme heat could have been a factor.

The Stanford estimates come amid growing concern in the scientific and medical communities over the potentially life-long harms caused by wildfire smoke exposure. Burke also predicted the coronavirus pandemic and systemic racism and inequality worsened the toll. “There’s evidence that exposure to air pollution worsens COVID-19 outcomes [and] there’s this socioeconomic and racial gradient to COVID-19 outcomes,” he said. “We see much worse outcomes among many minority groups.”

Both extreme heat and wildfires are made worse and more likely by climate change, which is caused by burning fossil fuels. “If we’re in this for the long haul (because) climate change isn’t going away, we really need to stay on top of this,” Dr. Stephanie Christenson, an assistant professor and pulmonologist at UC San Francisco, told the Chronicle. (San Francisco Chronicle, Sacramento Bee, Chico Enterprise, ABC-7 KGO News, AP, KTVU, Insider, Weather Channel; Long-term damage: Vox; Climate Signals Background: Extreme heat, Wildfires, 2020 Western wildfire season)