The data is collected and verified by AirVisual. Where official monitoring data is not available or is not complete, AirVisual collects air quality data from consumer-grade air quality sensors. While readings have been validated against high-grade air quality monitoring stations in multiple locations, reliance on consumer-grade sensors entails a higher degree of measurement error. Greenpeace understands the limitation that the rankings are subject to measurement error and so they are indicative, not absolute.
Air quality ranking disclaimer
About IQAir
ABOUT IQAIRIQAir is a Swiss technology company that empowers individuals, organizations and governments to improve air quality through information and collaboration.
