New research found that after the US sdministration suspended its embassy air pollution monitoring initiative, air pollution increased by 23-33%, particularly in Southeast Asia and sub-Saharan Africa, where reliable monitoring data is scarce.

The US’s abrupt shutdown of its embassy air pollution monitoring program in 2025 hit regions with little publicly available data the hardest, says a study published in PNAS, which analyzed air pollution levels before and after the program suspension. 

Using satellite-based measurements, researchers from Columbia and Hong Kong Universities found that there was a clear pattern of higher air pollution after the program was shut down, particularly in areas with “poor substitutes” for US-provided data. 

Their modeling estimates a 33% increase in air pollution across the 46 cities in their study. That increase translates to roughly three times the World Health Organization (WHO) annual guidelines for PM2.5 concentrations – the fine particulate matter that can travel most deeply into the body and cause a host of cardiovascular, respiratory, and reproductive health issues. 

Independent environmental monitoring, which the US Department of State program offered until being shut down by the current Trump administration during DOGE cuts in 2025, led to lower pollution where autocratic or repressive governments withheld domestic air quality data.

For nearly two decades, US embassies and consulates have publicly reported real-time air quality worldwide, providing oftentimes the only reliable source of air quality data in some countries. 

The findings emphasize the precariousness of pollution reductions in lower-and-middle income countries without publicly accessible and trusted pollution information–and come at a time when environmental transparency is increasingly threatened. 

Regions with little monitoring face outsized impact

Dr Zoey Zhou, the lead study author and a climate researcher at Columbia University, explained that the places most dependent on embassy data “were those with few publicly accessible alternatives, either because domestic monitoring was limited or because the readings were not shared with the public.

She said that pollution increases were “largest and most persistent in places with poor substitutes for the embassy data,” and she wasn’t surprised the program suspension would lead to such a notable increase in pollution. 

Across the study sample embassy and consulate locations, Southeast Asia saw the largest spike in air pollution, followed by sub-Saharan Africa and South Asia, Zhou told Health Policy Watch.

“Latin America and North Africa appear lower on average. But each regional group contains only a small number of sites, so I would describe these as suggestive patterns, rather than a definitive ranking of regions or countries,” she cautioned.

These patterns mirror recent analyses showing large disparities in philanthropic funding for clean air – with Africa and Latin America receiving only about 1% and 2% of funding, respectively. 

See related story: https://healthpolicy-watch.news/regions-with-worst-air-pollution-receive-least-amount-of-funding/

Her study also highlights the outsized role of the US State Department air quality monitoring program for citizens in countries who would otherwise have little knowledge of the state of their air. 

This holds for larger bodies such as the WHO, which relies heavily on embassy data for its consolidated air pollution data repository in about 25 cities worldwide.  

Two decades of monitoring

An undated picture of air pollution in Beijing – the US State Department began its embassy air pollution monitoring program here in 2008 to provide reliable, timely, and accessible data.The embassy program began nearly two decades ago in Beijing. In 2008, the city faced intense scrutiny over its air quality prior to the Summer Olympic Games, with concerns that the smog would not only interfere with athlete performance but could also be dangerous to competitors with asthma. 

And while the country saw historic wins in cleaning up its air since the Games, the US Department of State set a precedent of air quality monitoring in countries with limited public environmental data. 

“Now the Department’s ZephAir mobile application displays EPA [US Environmental Protection Agency] air quality index information and health messaging for more than 80 overseas locations, with data from reference-grade monitors at U.S. embassies and consulates and other government partners,” the department’s website reads.

Past research has shown that the program reduced air pollution concentration levels by 2-4 microns per cubic meter – roughly 40-80% of the WHO’s recommended annual PM2.5 limit – with particularly significant drops in low-and middle-income countries where monitoring is often scarce.

No more public accountability

When asked about exactly why air pollution could have so quickly spiked after air quality data went dark, Columbia’s Zhou acknowledged her team is still searching for an answer. 

“Unfortunately, we cannot say exactly which mechanism drove the increase, or separate the role of public awareness from enforcement. It is difficult to draw a clean line between the two because, in practice, they operate as a reinforcing feedback loop rather than two independent levers.”

Despite the difficulties in understanding exactly what drove the poorer air quality, Zhou pointed to research showing that making information publicly available strengthens accountability. 

“When reliable data are accessible to everyone, government agencies can investigate, businesses can respond, and citizens and journalists can press for action. That shared evidence keeps pressure on polluters and authorities to improve air quality. When that information disappears, some of that pressure weakens.”

Furthermore, controlling pollution is an expensive and continuous operating cost – one in which manufacturers can turn off abatement devices to save electricity, use fewer chemical solvents, or switch to cheaper, dirtier fuels, she explained. In other sectors, like trash burning enforcement, dust suppression at construction sites, and agricultural burning bans, rely on public oversight.

“It makes the case even stronger that relatively low-cost investments like basic open data infrastructure is a no-brainer investment in countries with little existing monitoring,” said Christa Hasenkopf, director at University of Chicago’s Clean Air Program and who was not involved in either study. 

“Once the public has access to open data relevant for their lives, they want to keep that access,” she said. Her group, part of the Energy Policy Institute at the University of Chicago (EPIC) accepts grant applications – and saw 76% of applicants propose work in countries that lost data when the State Department program ended.

Access to data connected to cleaner air

With some 300 million people living in cities with a US embassy monitor in 2019, researchers from Carnegie Mellon University and The University of Queensland have estimated that publicizing embassy data – and giving advocates and the public access to air quality  information – produced upwards of $127 million annually due to lives saved from lower air pollution. 

The 2022 study notes that, prior to 2008, “there were virtually no [particulate matter] monitors in non-[Organisation for Economic Co-operation and Development] countries.”

Ten years later, a third of non-OECD countries in the study sample had some form of particulate matter monitoring, with roughly one in five of these low- and middle-income countries having only local monitoring, and 7% having only embassy-administered monitoring. 

Furthermore, embassy readings are seen as more credible than those operated by local governments in many of these countries–where watchdogs have documented the tampering or manipulation of air pollution monitors. Last year, India’s capital was accused of spraying water around its monitors to make its smog situation appear less dire.

When asked for comment as to the suspension of the program, a State Department spokesperson told Health Policy Watch that the department is in the process of restoring public reporting of its air quality monitoring data and had no further comment about why the program had been discontinued.

Image Credits: The Week, Kentaro Iemoto/Flickr, PNAS/ Zhou et al, Chetan Bhattacharji/HPW.