Just how bad are the wildfires in the West? The Los Angeles Times reports that roughly half of all Californians are exposed to air that exceeds safety thresholds for tiny particles known as PM2.5. That equates to about 20 million people. "Rarely have so many Californians breathed such unhealthy air," declares the story. On Thursday, one wildfire in northern California became the state's largest on record, with more than 735 square miles torched by the August Complex fire, per the AP. The fires also are affecting Washington state and Oregon. See AP images below. (More wildfires stories.)