ENVIRONMENTAL HEALTH HAZARD INDEXSummary The environmental health hazard exposure index summarizes potential exposure to harmful toxins at a neighborhood level. Potential health hazards exposure is a linear combination of standardized EPA estimates of air quality carcinogenic (c), respiratory (r) and neurological (n) hazards withiindexing census tracts. Where means and standard errors are estimated over the national distribution. Interpretation Values are inverted and then percentile ranked nationally. Values range from 0 to 100. The higher the index value, the less exposure to toxins harmful to human health. Therefore, the higher the value, the better the environmental quality of a neighborhood, where a neighborhood is a census block-group. Data Source: National Air Toxics Assessment (NATA) data, 2011. Related AFFH-T Local Government, PHA and State Tables/Maps: Table 12; Map 13. References:https://www.epa.gov/ttn/atw/natamain/ To learn more about the Environmental Health Hazard Index visit:https://www.hudexchange.info/resource/4868/affh-raw-data/Date of Coverage:02/2018