Air quality in Norway

EAQI from the European Environment Agency is based on four pollutants: particulate matter PM2.5 and PM10, nitrogen dioxide (NO₂) and ozone (O₃). The scale runs from 0 (good) to 100+ (very poor). Values <20 are good, 20-40 fair, 40-60 moderate, 60-80 poor, 80-100 very poor. Official Norwegian measuring stations: NILU (luftkvalitet.no).