Air Quality

The United States has made significant progress in reducing air pollution levels since the 1970s, when the Environmental Protection Agency (EPA) began regulating air quality. However, poor air quality continues to pose risks to public health in areas across the United States. EPA has reported that about 40% of the U.S. population lives in areas where air pollution levels exceed limits set to protect public health. In addition, the U.S. has recently experienced some of its worst wildfire seasons on record, creating unhealthy smoke that affected air quality for tens of millions of Americans. 

The Clean Air Act, as amended, establishes the legal framework for air quality management in the United States. EPA oversees the tools used to manage air quality, such as the national air quality monitoring system. Some of these tools are outdated, however, and may not adequately support modern air quality management needs or take advantage of new technologies.  

Key issues related to managing air quality include:

• Monitoring. EPA and state and local agencies, which cooperatively manage the air quality monitoring system, face challenges meeting evolving air quality information needs—such as information on local air pollution hot spots and air toxics. To address these challenges, EPA should develop a modernization plan for the air quality monitoring system. 

Air Quality Monitoring Site

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• IT systems. EPA primarily uses two legacy IT systems to manage air quality data. These aging IT systems present maintenance and usability challenges for EPA and other users, such as tribal, state, and local air agencies. EPA is considering replacing these systems with a new one, and the agency should document the need for and cost of a new system.
• Wildfire smoke. EPA’s efforts to help communities prepare for and respond to increasingly frequent wildfire smoke episodes have been ad hoc and spread out across the agency. EPA could better coordinate internally on these efforts. EPA could also enhance its role in supporting certain wildfire risk mitigation efforts, such as the “prescribed burns” that land managers use to decrease the intensity of wildfires.

 Examples of Wildfire Smoke Effects on Air Quality

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• Sensors. Technological improvements have led to the development of air quality sensors that can be deployed virtually everywhere. These sensors can help fill in air quality monitoring gaps and provide additional information to understand air pollutants. However, sensors are not yet available for some air pollutants, and ensuring the quality of sensor data can be challenging. Policymakers (legislative bodies, government entities, academia, industry, and other groups) could take certain actions—such as supporting innovation in sensor technologies or improving access to guidance on sensor use—to help address challenges to developing and using sensors.
• Vehicle pollution. Federal laws provided over $5 billion for programs to help replace existing school buses with less-polluting ones, such as electric or propane buses. EPA reports high demand for the programs, which have helped fund nondiesel buses in school districts across the country. But EPA could better assess progress toward program goals, such as gathering information to verify bus deployment and developing a more complete methodology for estimating emission reductions.