https://www.wired.com/story/wildfire-smoke-pandemic/

At some point this autumn, the people of the San Francisco Bay Area will very likely wake up to find that the air smells of smoke, even indoors, and their cars are coated in ash. A hundred miles to the northeast, in the state’s ever drier forests, a massive wildfire will be burning, fanned by strong seasonal winds that will carry the smoke into the lungs of millions of people. The asthmatic will suffer the most, but the plummeting air quality will elevate the risks of respiratory diseases like pneumonia and tuberculosis. This year they’ll face an additional menace: Covid-19.

A galaxy of conspiring factors, including climate change and land misuse, have turned the California landscape into a tinderbox that now burns with incredible and reliable ferocity. In 2017 came the Tubbs Fire, which caused $1.2 billion in damage and killed 22. In 2018, it was the Camp Fire, which virtually obliterated the 30,000-person town of Paradise, killing 86. Last year it was the Kincade Fire, which burned almost 80,000 acres. Each has flung massive clouds of smoke into the air, infiltrating the lungs of the firefighters and evacuees on the frontlines, and even more people downwind.