Those of us in the San Francisco Bay Area woke up to the smell of smoke on Monday morning, the result of the fires that burned on Angel Island through the night scorching about 400 acres.  Wildfires also burned in nearby Napa country throughout the weekend.  While we know that inhaling all that smoke can’t be a good thing, a new study out from the National Center for Atmospheric Research (NCAR) has quantified some of the risks, and what they’ve found is dangerous amounts of ground level ozone.

The study, which focused on California’s wildfires September and October of last year, found that the fires repeatedly boosted ozone to unhealthy levels – levels that exceed U.S. health standards — across much of California and Nevada.

While ozone in the upper atmosphere where it blocks ultraviolet radiation from the sun is a good thing for life on Earth, it’s a bad thing down here at the surface where ozone can cause breathing difficulty and aggravate respiratory problems like asthma and emphysema in humans and it can harm agricultural crops.  The EPA’s brochure on “good” and “bad” ozone identifies ozone as the main component of urban smog.

Many climate scientists are predicting hotter and drier weather for the American West, likely increasing the frequency and duration of wildfires.  “Bad” ozone might be something we’ll be getting used to.

Here’s a July article from the San Francisco Chronicle with an overview of California’s fires for the first half of 2008.