MAIA Air Sensor at Work in Addis Ababa

This roof-mounted air sensor in Addis Ababa, the capital of Ethiopia, is one of ten instruments used by NASA’s Multi-Angle Imager for Aerosols (MAIA) to study the city’s air quality. MAIA’s sensors give detailed information about particulate matter 2.5 micrometers or smaller (PM2.5), a particularly dangerous form of air pollution. Black carbon, or soot, is a major component of Addis Ababa’s particulate pollution and comes from diesel vehicles, fires, and other combustion sources. Detailed MAIA measurements show how pollution varies by time of day and season, with spikes during rush-hour traffic and holiday celebrations. The results are relevant to cities worldwide, including in the United States. The 2025 State of Global Air Report cited in the study estimates about 4.9 million excess deaths per year linked to these particles; black carbon has been tied to low birth weight, impaired brain development, respiratory illness, and premature mortality.