Air Quality

Number of Unhealthy Air Days

Santa Clara & San Mateo Counties

Data Source:

United States Environmental Protection Agency, Outdoor Air Quality Data

Analysis:

Silicon Valley Institute for Regional Studies

Data are from the United States Environmental Protection Agency, Outdoor Air Quality Data, and include Santa Clara and San Mateo Counties. Unhealthy days are based on an Air Quality Index (AQI) of >100 for sensitive groups, and >150 for the general population in one or both of the two counties. The AQI includes Air Quality Index (AQI) for all AQI pollutants including carbon monoxide, ozone, particulate matter, nitrogen dioxide, sulfur dioxide, and lead. The PM2.5 monitoring network was phased in between 1999 and 2001 in most areas, so earlier years do not include PM2.5 (a type of particulate matter).

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Resources for Relevant Data and Reports (show)

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