Percentile
A statistical ranking that shows what percentage of a group falls at or below a given value. Being in the 95th percentile for pollution exposure means only 5% of areas are more polluted.
Related terms
Cumulative Burden Threshold A scoring cutoff (for example, the top 5% nationally for both poverty and pollution exposure) above which a neighborhood becomes officially designated as a disadvantaged or overburdened community, qualifying it for federal cleanup funds and protections. EJScreen The EPA's Environmental Justice Screening and Mapping Tool. It overlays environmental burdens (Superfund proximity, traffic, toxic discharges) with demographic vulnerabilities to identify disadvantaged communities. Statistically Significant A finding mathematically unlikely to be the result of random chance or coincidence. Used to confirm that a pattern—like a disease cluster—is real and not just noise in the data.