The data source name was changed by EPA from National Toxic Release Inventory (TRI) to National Emissions Inventory (NEI). The TRI tracks the 188 Hazardous Air Pollutants (HAP) emitted by fixed sources. The NEI combines TRI with other sources to produce estimates of total releases of HAPS from fixed and mobile sources.
The list of airborne toxics that pose the greatest threat to public health is updated Annually to reflect new information related to industry airborne emissions and revised assessments of the danger posed by specific substances. To assess progress for this objective, however, the list of airborne toxics monitored will be “frozen” to those included on the 1993 list to ensure comparability of updates during the monitoring period.