PM2.5 levels at 129.9 µg/m³ as health ministry urges residents to take precautions
KATHMANDU, MARCH 10
Kathmandu's air quality has deteriorated to hazardous levels, with the capital ranking as the second most polluted major city in the world as of Monday morning, according to real-time data from IQAir, the Switzerland-based global air quality monitoring platform.
The city's Air Quality Index stood at 210 between 9:00 and 10:00 am, placing it in the "very unhealthy" category, well above the threshold of 150 that is considered unhealthy and past the 200 mark that signals very unhealthy air. Only Delhi, which recorded an AQI of 302, ranked higher. Lahore followed Kathmandu in third place with 186, ahead of Dhaka with 181 and Yangon with 165.
Fine particulate matter, or PM2.5, the most dangerous category of airborne pollutant due to its ability to penetrate deep into the lungs, was recorded at 129.9 micrograms per cubic metre, more than 25 times the World Health Organization's recommended safe limit of 5 µg/m³. Coarse particulate matter, PM10, stood at 100.3 µg/m³.
Under Nepal's government-approved Air Quality Index scale, a reading of 0 to 50 is considered good, 51 to 100 moderate, 101 to 150 unhealthy for sensitive groups, 151 to 200 unhealthy, 201 to 300 very unhealthy and anything above 300 hazardous.
The Ministry of Health and Population has urged all residents to take precautions. According to the ministry, prolonged exposure to air pollution can cause serious damage to the heart, blood vessels, lungs, eyes and kidneys, and can contribute to conditions including asthma and cancer.
Kathmandu's chronic air quality problem stems from a combination of factors that compound each other. The valley's geography, surrounded by hills on all sides, traps pollutants and prevents them from dispersing. The city has a large number of ageing vehicles running on diesel and outdated engines, which are a major source of black carbon, carbon monoxide, nitrogen dioxide and sulfur dioxide. Open burning of waste and organic material, and construction dust, add to the pollution load.
The problem is at its worst between January and May, and again in November and December, when cold, still air settles over the valley and traps pollutants close to the ground. August is historically the cleanest month, when monsoon rains and wind clear the air.
Residents, particularly those with respiratory or cardiovascular conditions, the elderly and children, are advised to limit outdoor exposure, wear masks when outside and keep windows closed during peak pollution hours.