Wildfires can be a large source of health-harming PM2.5
During big wildfire years, California's average level of fine particulate matter, or PM2.5, can almost double. Air pollution research shows PM2.5 can harm human health.
A stacked bar chart show little change in non-fire PM2.5 and only small additions from wildfire smoke during years with few fires. But in big fire years, total PM2.5 from smoke almost doubles the statewide average.
