Q&A: Report highlights importance of satellite-derived air quality data for rural health

Key takeaways:

• Multiple U.S. counties do not have regulatory ground-based air quality monitors.
• Pulmonologists and patients with lung diseases/conditions should be aware of air quality and pollutant levels in their area.

With the known negative impacts of air pollution on health, especially in patients with respiratory diseases/conditions, lacking local air quality and pollution data can be detrimental to an individual’s well-being.

According to an American Lung Association press release, 2,700 U.S. counties had incomplete or no fine particulate matter (PM_2.5) monitoring data in 2020, 2021 and 2022, but a new report from the Association outlines a way to monitor air quality in these often rural areas.

The “Something in the Air: Bridging the Air Quality Data Gap with Satellite Technology” report found that satellite technology is beneficial for capturing air pollution data in settings without regulatory monitoring stations.

With more than one-third of Americans breathing unhealthy, polluted air where they live via monitoring data in the American Lung Association’s 2024 State of the Air report, the new report aimed to identify how many Americans living in counties without monitors are also living in these poor conditions.

Healio spoke with Lexi Popovici, MPA, senior manager of Nationwide Policy, Clean Outdoor Air for the American Lung Association and author of the report, to learn more about findings from the report, how air quality monitoring data informs pulmonologists and ways to advocate for stronger air quality standards.

Healio: What is satellite technology in the context of air quality/pollution? What are other ways air quality is measured? Which method is most commonly used?

Popovici: Satellite technology is a continuously evolving field that remains a promising and supplemental solution to understanding our nation’s air quality. Satellite technology uses sensors on satellites to detect gases and particles in the atmosphere. Scientists then use models and data fusion methods to translate this satellite data into estimates of ground-level pollution, which provides insights into air quality patterns, especially in areas with limited ground-based monitoring.

Other ways air quality is measured include ground-based instruments, such as regulatory monitors and community (low-cost) sensors, including sensors from PurpleAir. Ground monitors measure air pollution by capturing and analyzing samples of air to detect concentrations of specific pollutants.

Ground measurement is the most common method for monitoring air quality because of its high accuracy, reliability and ability to capture real-time, location-specific data that directly reflect the air people breathe at ground level. Regulatory monitors are the gold standard. Reliable for measuring pollutants such as PM_2.5, ozone and nitrogen dioxide (NO₂), these monitors follow strict guidelines to make sure the data are accurate and dependable. The U.S. Environmental Protection Agency (EPA) uses them to track pollution over time, assess health risks and enforce air quality laws.

Healio: What was the inspiration behind the report’s focus on this specific technology?

Popovici: The report’s focus on integrating satellite technology into air quality monitoring is driven by the opportunity to enhance coverage in a way that complements the existing robust data provided by the Lung Association’s “State of the Air” report. Satellite data can offer additional insights in regions where traditional ground-based monitoring may be less accessible, providing a broader view of pollutants such as PM_2.5 across diverse geographic landscapes. This integration enriches our understanding of air quality, especially in places where population growth, land use changes and wildfires are introducing new sources of air pollution and supports the mission of providing comprehensive air quality information for all communities.

Despite significant progress, the American Lung Association’s “State of the Air” 2024 report shows millions of Americans still face unhealthy air and found that 39% of people in America — 131.2 million people — live in places with failing grades for unhealthy levels of ozone or particle pollution.

This report aims to help provide a clearer picture of the air that millions are breathing in regions without ground-based monitors. Utilizing satellites to uncover air pollution in unmonitored counties provides critical air quality information to Americans and helps expand potential public health protections.

Healio: From your perspective, what were the main findings of this report?

Popovici: The report finds that while regulatory ground-based monitoring stations provide critical air quality data, many regions in the U.S. lack comprehensive coverage, particularly rural areas. In our 2024 “State of the Air” report, less than a third of U.S. counties had enough air quality data to be graded for at least one pollutant. Satellite technology offers a valuable supplement to help fill those gaps, delivering insight into the air quality in unmonitored areas.

As many as 300 of the 2,700 counties in the U.S. with incomplete or no monitoring data for annual levels of PM_2.5 in the 2024 “State of the Air” report had pollution levels that might have earned a failing grade if the monitoring data had been available. The report highlights six unmonitored counties as examples where satellite data indicate potentially concerning levels of particle pollution: Collin, Texas; Forsyth, Georgia; Marion, Oregon; Mohave, Arizona; St. Charles, Missouri; and St. Tammany Parish, Louisiana.

These six counties serve as examples of what many counties around the country could be facing, as these six counties fall in the worst 2% of our satellite-derived estimations of PM_2.5 for unmonitored counties.

Satellite-derived data help provide a more comprehensive approach to air quality monitoring by extending coverage over a wider landscape, revealing hotspots, pollution patterns and trends that can give millions of people in the U.S. greater insight into their air quality.

Healio: How does air quality monitoring data inform pulmonologists?

Popovici: Air pollution has detrimental effects on both respiratory and cardiovascular health. It can lead to breathing difficulties, increase the risk for serious respiratory infections, worsen lung diseases such as asthma and contribute to the development of lung cancer. Additionally, pollution is a known trigger for cardiovascular issues, including heart attacks and strokes. Air monitoring data can inform pulmonologists about specific levels and types of pollutant exposure that impacts their patients.

These data help inform diagnoses, tailor treatments and adjust care recommendations, particularly for vulnerable populations such as those with asthma, COPD and other respiratory conditions. Being aware of local air quality forecast and monitoring alerts can help pulmonologists correlate symptom exacerbations with pollution spikes and provide anticipatory guidance, such as advising patients to limit outdoor activities on days with poor air quality.

Healio: If the area a pulmonologist practices in lacks official monitoring, what can they do to make sure their vulnerable patients are properly cared for?

Popovici: Pulmonologists can take several proactive steps to ensure that their vulnerable patients receive appropriate care:

• Encourage patients to use air quality mobile apps, which incorporate data from satellite and nearby monitoring sites, to check daily air conditions.
• Recommend air quality monitoring apps, such as AirNow, which help patients stay informed about daily air quality, even in areas with limited official monitoring.
• Advise patients on ways to minimize their exposure, such as staying indoors on poor air quality days, using air cleaners at home on days with elevated levels of fine particles and avoiding physical activity outdoors when pollution is high.
• Point patients in the direction of potentially using satellite data, when publicly made accessible, and community sensor networks to help provide more information on specific pollutant exposure.

Healio: The release states that satellite-derived data can uncover hotspots, pollution patterns and trends related to air quality. Why are these three pieces of information useful as climate change progresses?

Popovici: These pieces of information are increasingly valuable as climate change progresses due to its role in identifying areas where air quality risks are intensifying.

Hotspots reveal regions with consistently high levels of pollution, which can indicate places where climate change-driven factors, such as extreme heat or increased wildfire activity, may be worsening air quality. Hotspots can also come from sources of pollution that put a disproportionate burden of unhealthy emission on a nearby community.

Pollution patterns offer insights into how air contaminants move and accumulate, helping to forecast periods and locations of poor air quality and understand the sources driving these changes.

Trends provide a critical long-term view, showing how climate-related shifts, such as prolonged droughts or changing wind patterns, are impacting air quality over time. Together, these pieces of information help public health officials and policymakers to prioritize resources, prepare for future risks and safeguard vulnerable populations.

Healio: The report recommends that the EPA “set strong, science-based standards for all criteria pollutants,” not just PM_2.5 . What does the American Lung Association believe the standards for ozone and NO₂ should be?

Popovici: For years, the Lung Association and other leading health organizations have called for stronger national limits on ground-level ozone and NO₂. The Clean Air Act requires that these limits be based on what the science says is necessary to protect human health, and the current limits are too weak.

We’re calling on EPA to set the ozone standard at no higher than 60 parts per billion (ppb). As for the NO₂ standard, we’ve been urging for years that it be significantly strengthened and note that Canada has much more protective standards than the U.S.’s of 60 ppb for the 1-hour standard and 17 ppb for the annual standard, both of which will be further tightened from 2025.

Strengthening these standards is critical for addressing the health impacts of pollutants such as particulate matter and ground-level ozone, especially in light of advancing scientific evidence on the dangers of air pollution. Stronger standards would enhance protections for vulnerable populations and communities disproportionately affected by poor air quality, ensuring that air quality regulations reflect the latest science on pollution's health risks.

Healio: Based on the findings from this report, what needs to be done at the state level?

Popovici: States should support research monitoring programs to justify future regulatory stations and use satellite data to supplement PM_2.5 monitoring as they plan pollution reduction measures in their State Implementation Plans, especially benefiting environmental justice communities.

Additionally, states need to ensure all regulatory monitors are included in Air Quality Index (AQI) reporting and update boundaries to improve accuracy, particularly in unmonitored areas. Integrating supplemental data such as that derived from satellites into air quality alert systems and collaborating across state lines for accurate AQI estimates, especially with the EPA on AirNow.gov data, will also enhance protections for public health.

Healio: How can pulmonologists and patients with lung diseases/conditions make sure action is being taken by the EPA and their state?

Popovici: Pulmonologists and patients with lung conditions can help ensure action from the EPA and their state by staying informed and raising their voices in support of air pollution protections. The Lung Association urges providers and patients to add their names in support of stronger national limits on ozone.

They can also participate in public comment periods on proposed air quality standards and state plans. By collaborating with local environmental and health organizations, they can amplify their impact and strengthen support for air quality improvements. Engaging with policymakers at the local, state and federal levels to advocate for policies prioritizing clean air, especially for vulnerable groups, is key. Tracking air quality reports and data allows them to monitor progress and push for updates in monitoring, policies and health-protective measures.

Air quality is central to the health and well-being of communities nationwide, yet millions of Americans are still exposed to harmful levels of pollution. This report underscores the need for action at all levels — federal, state and local — to strengthen air quality protections.

As we continue to gather more data and utilize advancing technology, it’s essential that we translate this knowledge into meaningful policies and initiatives. Protecting air quality isn’t just about addressing today’s health risks but about creating a healthier future for generations to come. From space to your place, it is critical to understand the air you are breathing.

References:

• New report: Satellite technology holds promise for communities without air quality monitors. https://www.lung.org/media/press-releases/fy25-something-in-the-air-release. Published Oct. 29, 2024. Accessed Nov. 5, 2024.
• Something in the Air: Bridging the air quality data gap with satellite technology. https://www.lung.org/getmedia/66d68ccb-7b4e-4d85-84f6-d2796fdda1ce/something-in-the-air-report.pdf. Accessed Nov. 5, 2024.
• State of the Air 2024 report. https://www.lung.org/getmedia/dabac59e-963b-4e9b-bf0f-73615b07bfd8/State-of-the-Air-2024.pdf. Published April 24, 2024. Accessed Nov. 11, 2024.