Bay Area Air Quality Among Worst In Nation

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Bay Area Air Quality Among Worst In Nation

As an industrial hygienist it came as a surprise that the American Lung Association recently ranked Bay Area air quality among the worst in nation for air pollution and particulates. Unhealthy levels of pollution were found in numerous parts of the country, but the San Francisco Bay Area was ranked sixth in the list of most polluted areas in the country.

Use the American Lung Association city tracker to find air pollution facts for your Bay Area city and county.

San Francisco Bay Area Air Quality, Bay Area air quality

San Francisco Bay Area Air Quality


Air quality and air pollution clearly vary by city and county.

Bay Area Air Pollution

Bay Area Air Pollution

What Bay Area counties have bad air quality?

Not only does Bay Area air quality vary dramatically from county to county, but the degree of variance between counties is dramatic. For instance the following counties received an “F” grade indicating unhealthy levels of pollution:

  • Alameda
  • Contra Costa
  • Sacramento
  • San Joaquin
  • Santa Clara

What Bay Area counties have the best air quality?

While these Bay Area Counties ranked very well for air quality, receiving an “A” grade from the American Lung Association:

  • Marin
  • Mendocino
  • Monterey
  • Napa
  • San Francisco
  • Santa Cruz
  • Sonoma


That is as dramatic a continuum as you can imagine. In part this shows how much micro climates, impacts of climate change, road traffic and wind patterns in the Bay Area impact local air pollution. San Mateo county was given a “B” by the American Lung Association, and Solano was given a “C.”

Grades measure two separate aspects of  air quality with a set if grades for “high ozone days,” and an entirely different set of grades available for “particle pollution.” There are significant differences between the two sets of data. For example, Marin County gets a “C” for particle pollution but an “A” for high ozone days.

If you’re considering purchasing a new building or want an existing building or site tested for air pollution, Healthy Building Science offers expert industrial hygiene services including air quality testing for particulates, VOCs, aldehydes and more. If you’re concerned after learning that Bay Area air quality is among the worst in nation, get a free quote for an air quality inspection and air quality testing. We service all of California and focus primarily on counties surrounding the Bay Area.