Never before has the air quality been this bad for this long in Northern California, at least in modern history.
Two years ago the Camp Fire caused 10 days of bad air; the Bay Area is now on 25 days of smoke.
"Many of us are worried about the cumulative effects of these bad air days on health," said Dr. John Balmes, member of the California Air Resources Board and Public Health Professor at University of California, San Francisco and UC Berkeley. "The research shows that short-term exposure to this kind of smoke will increase emergency department visits and hospitalizations for exacerbations of heart and lung disease."
The smoke is expected to linger for several days.
Dr. Balmes said while the air quality is poor people should stay indoors with windows shut, run their ventilation systems on "recirculate" with MERV 13 air filters or higher or use portable HEPA air purifiers and make sure to wear N95 masks if you must go outside.