Since 2020, ZephAir has provided real-time air quality data for about 75 U.S. diplomatic posts. Now, the public tool includes three-day air quality forecasts for PM2.5, a type of fine particulate matter, for all the approximately 270 U.S. embassies and consulates worldwide. These tiny particles, much smaller than a grain of sand, can penetrate deep into the lungs and enter the bloodstream, causing respiratory and cardiovascular problems.