NATA is a national scale screening analysis of air toxic emissions from all sources of outdoor origin. NATA provides risk estimates from disparate sources of air pollution to identify and prioritize the chemicals, sources, and locations that are of greatest potential concern in terms of contributing to population risk. 

RSEI is more narrowly focused on releases reported to the Toxics Release Inventory (TRI) and so provides a risk-related perspective on toxic emissions from industrial facilities, and allows screening and prioritization within those kinds of releases only.

RSEI models water releases in addition to air releases.

NATA predicts risks associated with air emissions only. 

RSEI uses TRI data on toxic releases from industrial facilities, which is a type of source included in NATA (although not all TRI facilities are included in NATA). NATA also considers background pollution, onroad and nonroad mobile sources, and smaller sources not reportable to TRI like dry cleaners.

NATA covers a subset of chemicals reportable to TRI, roughly one third, although many of the reportable TRI chemicals not covered by NATA have relatively low release volumes and lower toxicity.

RSEI is updated annually, and all years of TRI data (from 1988 to present) are included in each annual update to create a comparable time series data set. 

NATA is updated approximately every three years concurrent with updates to the NEI, and data from different years cannot be compared.

NATA’s results are expressed in terms of excess risk (for cancer effects) and hazard index (for non-cancer effects). 

RSEI facility-level results are usually expressed in terms of RSEI Hazard (pounds*toxicity) or RSEI Score (toxicity*dose*population). RSEI also produces geographically-based Microdata, with results expressed as toxicity-weighted concentration or RSEI Score.

NATA results can be examined by chemical and source type, at various level of aggregation from Census tract to the national level. 

RSEI results are designed to be filtered by one or more dimensions like industry, facility, chemical, year, state, etc. Metrics are additive and comparable across any aggregations. Using the Microdata, users can link cumulative potential burden in any specific geography with the facility releases potentially causing the impact.

NATA combines sources and modeling from different levels of resolution (that is, the locations of some of the sources are not as precise as the point sources), and so the lowest level of resolution at which the results are expressed is the census tract level.

RSEI sources are all point sources, and results are calculated at the level of the 810 meter grid cell, and can be summed to the census block level (which is more granular than tract).