Smoke from fires sweeping across California are filling the lungs of California’s children with smoke, with potentially long-term issues for life.

California as a whole has seen a steady uptick in smoke days in recent years. Counties in the state’s Central Valley, which already had some of the most polluted air in the state, were particularly hard hit by wildfire smoke this year. 

For children it matters where they live, how much foul air they breathewhether the family can afford an air purifier at home, and if they can afford to leave while ash rains down from the sky. 

Professor of medicine at Stanford, Dr. Kari Nadeau, who specializes in pediatric allergies and asthma, said she worried that the damage to children might last a very long time.  

It is well-established that long-term exposure to fine particulate matter pollution, the kind that comes out of the tailpipes of cars and trucks, increases the risk of asthma in children and compromises their immune systems. 

Nadeau’s research suggests that exposure to wildfire smoke, which contains the same particulate pollution and more, is associated with genetic changes in children’s immune cells. “It could,” she said, “have irreversible consequences.”