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TRI National Analysis

Air Releases

Air emissions reported to TRI continue to decline, serving as a primary driver of decreased total releases. Air releases include both fugitive air emissionsHelpfugitive or non-point air emissionsAll releases of the EPCRA Section 313 chemical to the air that are not released through stacks, vents, ducts, pipes, or any other confined air stream. and point source air emissionsHelpstack or point air emissionsAll releases of the EPCRA Section 313 chemical to the air that occur through stacks, confined vents, ducts, pipes, or other confined air stream..

This graph shows the trend in the pounds of chemicals released to air.


From 2007 to 2017:

In 2017:

  • Ammonia, followed by methanol, accounted for the greatest air releases of TRI chemicals.
  • Since 2016, air releases decreased by 2%.

This graph shows the trend in the RSEI Score for air releases.

  • The top chemicals by RSEI score for air releases were chromium and ethylene oxide.
  • Stack air releases tend to contribute relatively less to the RSEI score than fugitive releases because chemicals released through stacks tend to get dispersed over a wider area than fugitive air releases, resulting in lower average concentrations.
  • For a complete, step-by-step description of how RSEI models air releases and derives RSEI Scores from stack air emissions and fugitive air emissions, see “Section 5.3 Modeling Air Releases” in Chapter 5 (“Exposure and Population Modeling”) of EPA’s Risk-Screening Environmental Indicators (RSEI) Methodology, RSEI Version 2.3.6
  • For general information on how RSEI Scores are estimated, see Hazard and Potential Risk of TRI Chemicals.

This page was published in March 2019 and uses the 2017 TRI National Analysis dataset made public in TRI Explorer in October 2018.

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