CalEnviroScreen
Description
CalEnviroScreen, developed by California’s Office of Environmental Health Hazard Assessment (OEHHA), is a screening tool that scores and ranks census tracts across the state based on cumulative pollution burdens and population vulnerabilities. It combines data on pollution sources and exposures (air pollution, hazardous sites, traffic, drinking water, etc.) with sensitive population and socioeconomic indicators (e.g., asthma ER visits, cardiovascular disease, poverty, linguistic isolation) to identify communities that are disproportionately burdened by multiple environmental and social stressors.
Questions this resource can help answer
Which neighborhoods in California are among the most overburdened by pollution and vulnerability statewide?
In a given tract, which specific indicators (e.g., diesel PM, groundwater threats, poverty) are driving the high score?
How do environmental burdens in my community compare to others in my county or region?
Where should the state, cities, or agencies prioritize investments, enforcement, or grants aimed at environmental justice?
Are certain racial/ethnic or low?income communities more likely to live in high?scoring (high?burden) tracts?
How do I use this resource?
Go to the CalEnviroScreen webpage, open the interactive map, and zoom to an address, city, or census tract. The map shows each tract’s overall CalEnviroScreen score and percentile; click a tract to see detailed scores for pollution burden, population characteristics, and all underlying indicators. You can download the data tables and shapefiles for analysis, filter tracts (e.g., top 25% most burdened), and use the results in reports, grant applications, and planning documents.
Pro tips
Focus first on overall percentile and whether a tract is in the top 25% (state’s most burdened) before diving into details.
Use the pollution vs. population breakdown to see if a tract is high because of heavy pollution, high vulnerability, or both.
Turn on only a few layers at a time (e.g., traffic + diesel PM + poverty) to avoid clutter.
Always check the indicator year and definitions in the documentation before using numbers in a report.
Pair CalEnviroScreen with local data and community input; treat it as a screening tool, not a final risk assessment.
When downloading data, keep track of the CalEnviroScreen version (e.g., 4.0) you’re using.
Resource information
Technical specifications
CalEnviroScreen uses publicly available datasets—air and water pollution, hazardous sites, pesticide use, traffic, and other environmental indicators—plus health and socioeconomic data. Indicators are grouped into two major components: Pollution Burden (exposures + environmental effects) and Population Characteristics (sensitive populations + socioeconomic factors). Each indicator is converted to a percentile, then combined within its group; Pollution Burden is given extra weight. The final CalEnviroScreen score for each census tract is the product of the Pollution Burden and Population Characteristics scores, then ranked statewide so users can see which tracts are most highly burdened.
