Delhi’s poor AQI: Can air purifiers help?

More Delhi residents are relying on air purifiers to get them through the wintertime pollution, but what do experts say about this?

Life has turned upside down for Delhi residents as the air pollution level soars in India’s capital. Primary school students and college-goers returned to virtual classes, as during the COVID-19 lockdowns, while professionals who can work from home do so to protect their health. Gig workers and others with fewer protections face the challenge of maintaining their normal routines, while fearing they or their loved ones might end up in the hospital. Exercise routines have been suspended to limit exposure to toxic air, and GRAP (Graded Response Action Plan) Stage IV restrictions were implemented earlier this month.

On November 18, Dr. Shashi Tharoor, the Indian National Congress MP for Thiruvananthapuram, posted a graphic on X, showing Delhi as the most polluted major city in the world. He questioned, “Should it even remain the nation’s capital?” sparking mixed reactions online.

Mr. Haider Ali Khan, a journalist who works in Delhi, said the city’s air pollution has drastically affected visibility and health.

“The air pollution is making Delhiites choke every second,” he noted, pointing out widespread coughing, sneezing, throat clearing, and complaints of burning eyes.

Mr. Jude Francis Weston, a fellow journalist who commutes from Faridabad to Delhi, described a sharp decline in air quality on November 17 (AQI above 450), which made driving risky due to dense smog and poor visibility.

Even those who can afford to stay indoors are confined to rooms with air purifiers, trying to minimize their movement. But do these devices actually work?

At the heart of an effective air purifier is a HEPA (High Efficiency Particulate Air) filter, capable of removing 99.97% of airborne particles as small as 0.3 microns. Air purifiers come in diverse forms, from portable devices for cars to high-end models with Wi-Fi integration and real-time AQI reports. Popular brands in India include Dyson, PHILIPS, Quobo, Honeywell, and Xiaomi. Thousands of units have been purchased recently, as people brace for the winter’s toxic mix of Diwali firecracker fumes, agricultural stubble burning, and smog.