Air Sensors Potential for Regulatory Applications: US National Ambient Air Quality Standards and Other Uses
Citation:
Barkjohn, K., A. Clements, A. Holder, AND C. Mocka. Air Sensors Potential for Regulatory Applications: US National Ambient Air Quality Standards and Other Uses. Air Sensor International Conference, Riverside, CA, April 30 - May 03, 2024.
Impact/Purpose:
Impact Statement: Many air sensor users have questions about how sensors can be used for regulatory purposes. Sensors have a number of limitations and cannot be used for regulatory purpuses through the national ambient air quality standards (NAAQS). However, this data is still valuable for a variety of applications including supporting weight of evidence for air pollution health effects. This is an invited talk that will be presented to attendees at the 2024 Air Sensor International Conference in Riverside, CA.
Description:
In the United States, the Clean Air Act requires the Environmental Protection Agency (EPA) to establish National Ambient Air Quality Standards (NAAQS) and to monitor six common air pollutants. For NAAQS compliance, air quality instruments must adhere to stringent sampling, siting, and quality assurance requirements. The EPA’s Office of Research and Development must evaluate and designate instruments as Federal Reference Methods (FRMs) or Federal Equivalent Methods (FEMs) based on accuracy, precision, freedom from interferences, detection range, drift, and other key parameters. The FEM and FRM review process is resource intensive. Currently, both particulate matter (PM) and gas sensors have limitations that prevent them passing the rigorous FEM/FRM review process. Nonetheless, there is a burgeoning market for air quality sensors that, until recently, have been developed without specific guidelines for acceptable performance levels. In response, the EPA has developed sensor performance targets and testing protocols to evaluate their performance, providing a basic understanding of performance that is much less stringent than the FEM/FRM review process. In addition to variations in data quality requirements, the goals of sensor networks may differ from those of the NAAQS air monitoring network. While sensors are not used for NAAQS compliance monitoring, they can complement regulatory monitoring by offering a better understanding of spatial and temporal variations in local air quality, which is useful for determining the placement of regulatory monitors. The extensive collection of sensor-based air quality observations constitutes a valuable dataset for scientific research, supporting the regulatory process. For example, sensor data can be used to estimate exposure for population health studies, assess and enhance air quality model performance, and identify highly localized air pollution sources (e.g., hot spots or leak detection) that may warrant further rigorous investigation. Overall, these applications can support the weight of evidence analyses of air pollution health effects that are used in the integrated science assessments. These assessments form the scientific basis of the NAAQS limits. In addition, publicly displayed sensor data provides a means of communicating more personalized air quality information to impacted communities, potentially being more effective in raising awareness and encouraging actions to reduce exposure. Although this abstract was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.
