KATHMANDU, MARCH 22 Air pollution that had been afflicting the country, including the federal capital, Kathmandu, for quite some time has declined remarkably following rainfall last Friday. A week ago, the Air Quality Index (AQI) stood at 178, placing Kathmandu among the world's most polluted cities, ranking second globally. The AQI has since dropped sharply to 60, bringing Kathmandu down to the 67th position among the world's polluted cities. An AQI reading between 0 and 50 is considered 'good', while 51 to 100 indicates 'moderate' conditions requiring caution. Levels between 101 and 150 are deemed 'unhealthy for sensitive groups', particularly affecting individuals with respiratory and cardiovascular conditions. An AQI range of 151 to 200 is classified as 'unhealthy for all', 201 to 300 as 'very unhealthy', and readings above 300 as 'hazardous'. According to Gyanraj Subedi, Director General at the Department of Environment, the rainfall, coupled with strong winds, helped disperse dust and airborne pollutants, resulting in significantly cleaner air.