This is the final installment of a four-part series exploring how U.S. Embassies positively impact air quality monitoring around the world.

In March 2025, the U.S. Department of State announced that it would end its global air quality monitoring program, citing budgetary concerns (1). This decision will have far-reaching consequences for air quality data access and public health worldwide.

For over a decade, the State Department’s air quality monitoring program has provided real-time air pollution data from more than 80 embassies and consulates, filling critical monitoring gaps in regions where governments lacked their own means to track air pollution effectively.

Global impact of U.S. Embassy air quality monitoring

With a stated end date of March 2025, the program’s termination marks a significant shift in U.S. environmental engagement. For years, U.S. embassies and consulates in countries with limited air quality infrastructure have provided real-time, regulatory-grade air quality data to the public and policymakers. This data has been instrumental in shaping air pollution awareness, influencing policy discussions, and enabling communities to take protective measures against hazardous air conditions. 

This data has proven essential in changing air pollution policy in China and providing, at times, the only air quality monitoring in Central Asian and African countries. Air quality in the most polluted country in the world for both 2022 and 2024, Chad, was only made available in 2024 through U.S. State Department air quality data sharing.

With 75,000 employees around the world, the Department of State has a vested interest in ensuring personnel and their families have the data they need to make informed decisions to protect their health.

Beyond public health advocacy, the monitoring program also directly informed safety protocols for U.S. diplomats and their families stationed abroad. According to the State Department, they have “75,000 employees around the world” and “a vested interest in ensuring personnel and their families have the data they need to make informed decisions to protect their health (2).” Real-time data helped embassies assess air pollution risks and implement mitigation measures, establishing guidelines that minimize exposure to pollutants.

"For many cities, these monitors provided the only reliable real-time air quality data available. Without them, millions may be left uninformed about pollution risks." – Dr. Christi Chester Schroeder

"Ending this program is a huge setback for global air quality transparency," said Dr. Christi Chester Schroeder, Air Quality Science Manager at IQAir. "For many cities, these monitors provided the only reliable real-time air quality data available. Without them, millions may be left uninformed about pollution risks."

Role of U.S. monitoring in global air quality improvements

The U.S. State Department air quality monitoring program played a pivotal role in improving air quality worldwide by providing high-accuracy, regulatory-grade data. This data helped calibrate and validate thousands of low-cost air quality sensors used by local governments, NGOs, and researchers, improving the reliability of broader air quality monitoring efforts. By establishing a trusted baseline, State Department monitors supported local initiatives and strengthened regional air pollution tracking capabilities.

State Department monitors directly contributed to measurable improvements in air quality. In China, for example, when U.S. embassies in Beijing and other cities began publishing real-time PM2.5 data, public awareness surged, and local authorities were pressured to act. This led to stricter emissions regulations, cleaner industrial practices, and significant reductions in fine particulate matter pollution over the following years. 

Cities with a U.S. monitor saw substantial reductions in fine particulate concentrations, lowering the risk of premature death for more than 300 million people.

A 2022 study published in the Proceedings of the National Academy of Sciences found that when U.S. embassies began tracking local air pollution, host countries took action (3). Since 2008, cities with a U.S. monitor saw substantial reductions in fine particulate concentrations, lowering the risk of premature death for more than 300 million people.

Diplomacy and international partnerships

The air quality monitoring program has been widely regarded as one of the most cost-effective initiatives undertaken by the State Department (4). The program not only protected U.S. personnel abroad but also enhanced transparency in foreign countries, often holding local governments accountable for pollution levels.

Accurate and reliable data fostered goodwill with local populations, as residents, researchers, and policymakers increasingly relied on the embassy monitors to understand air quality trends. This data-driven diplomacy helped strengthen international partnerships in environmental health, encouraging governments to address pollution concerns more proactively.

The decision to halt data transmission is expected to save only tens of thousands of dollars—a modest cost given the program’s global reach and public health value (5).

Air quality monitoring program ends

Ending the State Department air quality monitoring program will create significant data gaps, particularly in regions where independent monitoring has been scarce. 17 years of data have been removed from airnow.gov, erasing a vital record of global air pollution trends and public health benchmarks (6).

Some countries will lose access to real-time air quality data, leaving millions without a reliable source of information on pollution levels.

For many countries, U.S. embassy monitors were the only source of real-time, validated air quality data—without them, transparency and public protections will be severely diminished.

The lack of regulatory-grade data will also diminish transparency, making it harder for journalists, researchers, and policymakers to track pollution trends and hold governments accountable.

The future of air quality data and monitoring

With the end of the U.S. Department of State air quality monitoring program scheduled for the end of March 2025, there is an urgent need for new solutions to fill the gap left by this critical data source. Global air quality monitoring efforts must continue to ensure that the public remains informed about pollution and equipped to make health-conscious decisions.

Through partnerships and innovations, communities can maintain access to real-time air quality data of low-cost sensors, despite the loss of the embassy network. However, regulatory-grade monitors provided by the U.S. Department of State will still be needed to help calibrate and validate low-cost sensor data.

The takeaway

The end of the U.S. Department of State air quality monitoring program marks a significant setback for global air quality transparency and public health. This program has been instrumental in providing reliable, real-time data to regions with limited air quality infrastructure, empowering local communities and governments to take action against pollution.

As U.S. embassies withdraw their data, the international community faces a challenging road ahead in maintaining air quality monitoring efforts and ensuring that vulnerable populations can access public health information. If the U.S. continues to withdraw from its global commitment to public health and safety, it will require collaboration, innovation, and sustained commitment from other governments, NGOs, and international organizations to fill the gap left by the program’s termination.