The air in Delhi was close to clean yesterday. This marked the first time this had happened in nearly a year. The news is a welcome respite for the 18.6 million residents of the national capital. But how long will it last?
The Air Quality Index (AQI) assesses air quality by assigning values between 0 and 500. The air is judged to be “good” (0-50), “satisfactory” (51-100), “moderate” (101-200), “poor” (201-300), “very poor” (301-400) and “severe” (401-500). On Friday, June 29, Delhi’s AQI value was 83. This placed the capital firmly in the “satisfactory” range. It was the best reading for the city since August last year, according to the Central Pollution Control Board.
“Monsoon winds cleaned the dusty air”
Delhiites can thank the monsoon season for the relief. “The monsoon winds cleaned the dusty air and brought the air quality to satisfactory level,” said meteorologist Gufran Beig, programme director of System of Air Quality Forecasting and Research (SAFAR). Rains also helped to alleviate high temperatures which have been blasting the capital in recent weeks.
Delhi is infamous for its poor air quality. Mid-June saw pollution levels in the city hit severe levels. Dust storms in neighbouring Rajasthan were believed to be at fault. The dust became “a carrier of toxic pollutants” according to Anumita Roy Chowdhury of the Centre for Science and Environment. Pollution levels were “8-9 times higher than normal” for the time of year. The pollution was so severe that the smog’s toxicity exceeded what could be read by government pollution monitors.
“Dangerously unhealthy snowglobes”
Pollution in Delhi is far from an atypical occurrence. However, the city’s “pollution season” usually takes place much later in the year.
“The smog season in northern India…will last for much of the upcoming winter,” the US-based National Oceanic and Atmospheric Administration (NOAA) said in November last year. “That means there are plenty of more opportunities for cold, stagnant air to fill with pollution, turning cities into dangerously unhealthy snowglobes.”
Delhi experienced an especially severe smog season last year. Chief Minister Arvind Kejriwal likened the city to “a gas chamber”. Severe and, in some instances, literally immeasurable levels of pollution exerted a fierce chokehold on the national capital. Schools and construction sites closed. The Indian Medical Association (IMA) declared a public health emergency.
The mid-June pollution crisis served as a reminder that Delhi’s poor air quality is not a public health problem reserved for the winter months. Rather, it is one the city’s inhabitants and officials have to be conscientious of all year round. The current respite for Delhiites is certainly welcome. However, it will not last.