An analysis by state environmental agencies scores and maps more than 8,000 census tracts statewide by how affected they are by multiple sources of pollution. Many of those showing the highest pollution burden are in Southern California. For a detailed explanation of categories and specific pollutants, view the report upon which this is based. On a tablet or desktop, use the search field to find pollution levels for any census tract in California. Try an address or ZIP Code and be sure to include the state (CA) in either instance.