Air pollution after the shutdown of US embassy monitoring.

Suspension of US embassy air-quality reporting in 2025 led to a 24-33% increase in local pollution levels across 46 cities, equivalent to roughly 1.9 µg/m3 PM2.5.

• Why it matters: Reliable, independent air-quality data influences public health policies and awareness; its sudden absence risks undermining pollution control efforts and public safety.
• What they did: Researchers used satellite-derived aerosol optical depth data and a difference-in-differences approach with control cities to assess pollution changes before and after reporting stopped, calibrating AOD to PM2.5 levels.
• The result: The study shows that removing trusted data sources can cause significant pollution increases, especially in cities lacking alternative monitoring, highlighting the importance of continuous environmental data for pollution management.