A river of dust and sand combined with man-made air pollutants to send levels of particulate matter soaring across India’s northern tier beginning on Tuesday, the Hindu reports. Sensors scattered across the capital city show the air quality index (AQI) for the most dangerous type of particulate matter, PM2.5, ranging from “unhealthy” to “hazardous” over the past 48 hours. A standard metric for reporting air quality in terms of public health risk, the AQI ranges from 0 to 500, with scores over 150 considered unhealthy and scores over 300 deemed hazardous, meaning the entire population is at risk from exposure.
Levels of the larger PM10 particles have, in general, been even worse. In some locations, PM10 sensors have repeatedly maxed out over the past two days, with the AQI registering as 999, air quality speak for ¯\_(ツ)_/¯.
Alexandra Karambelas, a postdoctoral researcher at Columbia’s Earth Institute studying the health effects of air pollution exposure in India, told Earther that short-term pollution episodes like this “can cause discomforts like coughing and lung irritation or they can exacerbate existing chronic illnesses such as asthma or other lower respiratory infections.”
On Friday, European Centre for Medium-Range Weather Forecast scientist Mark Parrington tweeted a PM10 analysis by the Copernicus Atmosphere Monitoring Service, which reveals the choking pollution levels extend across most of northern India and western Pakistan.
This isn’t northern India’s first rodeo with blinding, dust-filled nightmare days of late. Just last month, wild dust storms brought on by a combination of extreme heat and powerful downdraft winds smothered the same region, leaving more than 100 dead and affecting over 100 million.
The region has been unusually hot for much of the spring, causing India’s dry season to become even drier than usual and priming the region for dust storms.
Of course, dust storms aren’t the only atmospheric hazard New Delhi has to deal with. The city is also famous for its man-made air pollution, so much so that it even has its own “pollution season” in the fall. As the Hindustan Times noted on Friday, residents may have to get used to this being a year-round thing rather than a seasonal nuisance as temperatures rise and dry spells lengthen.
But in the meantime there’s a merciful reprieve in sight: India’s Meteorological Department says the density of dust in the air is now on the downswing, with the development of showers leading into the weekend likely.
Update 6/18: Air quality in India’s capital is back to something resembling breathable thanks to rainfall and a shift in the wind patterns over the weekend, the Hindustan Times reports. Most air quality sensors throughout the city are now registering AQI values in the ‘unhealthy’ category. Progress!
Correction: An earlier version of this article cited a Guardian report stating that dust pollution in New Delhi was responsible for trapping additional heat in the city and sending temperatures above 40 degrees Celsius. India’s Department of Meteorology later told Earther that this was not the case—dust does not trap heat in this way. Earther has removed the original claim from the story. We regret the error.