Kathmandu air pollution hits record high

Air pollution in Kathmandu

Winter inversion, vehicular emission, wildfires, and cross-border industrial pollution have combined to give Kathmandu Valley the worst air quality among cities in the world this week, adding to the risk of respiratory complications for Covid-19 patients.

On Monday night, the Air Quality Index (AQI) in parts of Kathmandu crossed 500, according to measurements at the US Embassy measuring station at Phora Darbar. It remained at above 500 from 10PM till 5AM, falling to 480 at 7AM on Tuesday.

NASA Worldview image of Nepal wildfires
A NASA Worldview satellite image of Nepal on 3 January showing the spread of smoke from wildfires in Kaski, Lamjung, and Dhading. Combined with vehicle and crossborder pollution,Kathmandu's AQI count hovered at 500 for the second straight day.


The Department of Environment’s own measuring station in parts of Kathmandu showed the AQI staying above 400 all day on Monday. Other global AQI measurement sites like IQAir put Kathmandu’s pollution level at 487 – the highest among cities in the region.

AQI Kathmandu

New Delhi’s AQI levels, which have been consistently high all winter because of crop residue burning as well as vehicular and industrial pollution, got a respite on Monday because of rainfall. At a time when Kathmandu’s AQI was hitting record highs on Tuesday morning with 438, the New Delhi suburb of Noida recorded less than 151 (AQI World map, below).

New Delhi and Kathmandu AQI levels
AQI levels in north India and Nepal on 5 January at 8AM showing Kathmandu's much higher pollution levels compared to New Delhi.

AQI is a composite measurement of the concentration of particulate matter below 10 and 2.5 microns, carbon monoxide, sulphur and nitrogen dioxide and ground ozone. AQI level between 0-50 is ‘Good’, 51-100 is ‘Moderate’, 101-150 is ‘Unhealthy for Sensitive Groups’, 151-200 is ‘Unhealthy’, 201-300 is 'Very Unhealthy', and anything above 301 is regarded as 'Hazardous'. Kathmandu's AQI has remained at the Maroon 'Hazardous' level for two days in a row. 

The US Environment Protection Agency (EPA) has also colour coded various AQI levels at Green, Yellow, Orange, Red, Purple, and Maroon. The World Health Organisation (WHO)’s guidelines state that AQI should be below 35, and the concentration of particles below 2.5 microns should be below 25 μg/m³over a 24 hour period. This means Kathmandu's pollution has been 15 times higher than the WHO standard.

AQI measurement guide

In Nepal, a Cabinet decision last year adopted the Department of Environment’s guidelines for air pollution to declare a health emergency if AQI exceeded 300 – meaning the government can ban open burning, close factories, and take measures to reduce vehicles on the roads. 

The government, which has been engulfed in a crisis within the ruling party after Prime Minister K P Oli dissolved the Lower House and called for snap polls in April-May, seems to be too distracted to pay attention to the converging crises of Covid-19 and air pollution.

Bhushan Tuladhar tweet

“This is a grave threat to public health, the government should have declared an emergency and taken urgent measures to curb pollution,” says environmental expert Bhushan Tuladhar. (left)

The air pollution emergency in Kathmandu puts the elderly, those with asthma and other respiratory ailments at high risk, and would be especially dangerous to those with Covid-19. 

AQI RatnaparkAQI rank by city

Poor air quality in Kathmandu and inside rural homes due to smoky kitchen fires kill far more people across South Asia than SARS-CoV-2. However, the record-breaking pollution this winter will add to the risk of the coronavirus.  

Even before Covid-19, the World Health Organisation (WHO) had warned that poor air quality in northern India and the Tarai was already the reducing average lifespan of tens of millions of people by 3.7 years.

“Long-term exposure to air pollution can cause many of the health conditions associated with increased vulnerability to Covid-19, such as diabetes and chronic heart and lung diseases,” said the State of Global Air 2020 released last October. 

Patan School Lalitpur clock tower
The clock is ticking for Kathmandu to act on reducing the health hazards of air pollution.

The report says that 100% of the population in India lives in areas where PM2.5 levels are higher than the WHO Air Quality Guideline. Nepal is not far behind with 98% of its people living in such areas. 

More than 65% of all deaths due to chronic obstructive pulmonary disorder (COPD) in 2019 were linked to air pollution in Nepal.

Says Pallavi Pant, air quality scientist at the Health Effects Institute: “Exposures to air pollution have been shown to affect the human body’s immune defence, making an individual more susceptible to respiratory infections such as pneumonia.” 

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