This coverage can be used for basic applications such as viewing, querying, and map output production, or to provide a basemap to support graphical overlays and analyses of geospatial data.

SUMMARY The Air Pollutant Exposure Zone (APEZ) map identifies areas in San Francisco where air modeling indicates higher levels of air pollution. This map is required to be updated every 5 years, as established in San Francisco Health Code article 38. The 2025 Air Pollutant Exposure Zone map is an update to the 2020 map. Additional information may be found at Air Quality Review | SF Planning.

HOW THE DATASET IS CREATED The 2025 APEZ update modeled areas of the city where: particulate matter (PM2.5) is greater than or equal to 9 µg/m3 or where the risk of cancer from air pollutants is greater than or equal to 100 in a million; in health vulnerable ZIP codes (94102, 94103, 94110, 94124, and 94134), where the risk of cancer from air pollutants is greater than or equal to 90 in a million; locations within 500 feet of freeways; or locations within 1,000 feet of roadways with a daily average of 100,000 vehicles. To learn more, visit San Francisco Citywide Health Risk Assessment: Technical Support Documentation, Air Pollutant Exposure Zone Handout and Air Pollutant Exposure Zone Story Map.

UPDATE PROCESS Updated every five years.

HOW TO USE THIS DATASET The City uses this dataset as follows. San Francisco Health Code article 38 requires new developments or major renovations within the APEZ with sensitive receptors, like housing or preschools, to include a ventilation system that sufficiently removes fine particulate matter (minimum efficiency reporting volume [MERV] 13 or equivalent filtration). In addition, Environment Code Chapter 25 requires public agencies implementing projects within the APEZ to use the cleanest construction equipment available. The City’s environmental review under the California Environmental Quality Act (CEQA) uses the APEZ in its analysis to mandate the use of clean construction equipment, when applicable. To learn more, visit Air Quality Review | SF Planning.