Where does ecological research fit into the process of setting air quality standards? An overview of the role of ecological data in the ozone rulemaking

Background/Question/Methods

The Clean Air Act calls for EPA to issue and periodically review National Ambient Air Quality Standards (NAAQS) for the “criteria” pollutants.  Criteria pollutants include ozone (O₃), particulate matter (PM), carbon monoxide (CO), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), and lead (Pb).  The review of the NAAQS includes consideration of both effects on human health (primary NAAQS) and effects on welfare (secondary NAAQS).  The definition of welfare includes, but is not limited to, soils, water, wildlife, vegetation, visibility, weather, and climate.  Effects on components of ecological systems are, therefore, an important consideration in the periodic review of the secondary NAAQS conducted by EPA.

The recent review of the secondary O₃ standard provides a good example of how ecological research has been incorporated in the review of that standard.  The questions addressed in this presentation are: 1) What ecological data was most helpful in the review of the O₃ standard? 2) What are the gaps in communication from basic research to informing policy-making?

Results/Conclusions

The Integrated Science Assessment (ISA) is an EPA produced document that summarizes the most policy-relevant science for the review of the NAAQS, including ecological science, and often includes input and authorship by researchers from the academic community.  The research summarized in the ISA is used as the foundation for EPA Risk and Exposure Assessments.  More than forty years of research has shown that ambient O₃ pollution can affect photosynthesis and growth in plants and this can have consequences for ecosystems.  Some of the most compelling studies for the NAAQS reviews occur in protected areas such as National Parks.  When dealing with O₃ effects research, it was extremely important that exposure information was available from the original studies in order to compare results across studies.  The exposure information is also essential for creating exposure-response relationships that help policy-makers consider the risks to vegetation and ecosystems at different levels of O₃ exposure.  These relationships can also be useful for inputs into larger scale ecosystem models.  Communication of research needs to the ecological research community remains a crucial step in the process of reviewing air quality standards.

This abstract does not necessarily reflect the views or policies of the U.S. EPA.