Chronic exposure to pollution from wildfires has been linked to tens of thousands of deaths annually in the United States, according to a new study. The paper, published Wednesday in the journal Science Advances, found that from 2006 to 2020, long-term exposure to tiny particulates from wildfire smoke contributed to an average of 24,100 deaths a year in the lower 48 states. "Our message is: Wildfire smoke is very dangerous. It is an increasing threat to human health," said Yaguang Wei, a study