For quite some years, Delhi has been carrying the championship flag of the most air polluted city in the world. A hidden flag for most of its citizens, who until recently genuinely believed that Beijing’s air pollution is significantly worse. This misconception dwelt in a tremendous lack of general awareness on the air quality in Delhi, as well as in the kind of air pollution prevailing in the city.

In fact, Delhi suffers from high concentration of very harmful coarse and fine particles. Particles less than 10 micrometers in diameter (PM) are directly inhaled and accumulated into the respiratory system. Particles less than 2.5 micrometers in diameter (PM) create an even higher health risk: as tiny as 1/30 the width of a human hair, they lodge deeply into the lungs. This is followed by all sorts of deceases and leads to terrifying WHO statistics: 600,000 air pollution related deaths per year in India. Now, comparative OECD data for PM10 ( 2010): 120 micrograms per cubic meter in Beijing versus 140 in Bombay and 280 in Delhi. We might feel the pollution smog less than in Beijing, but we experience it way more.

A sudden rise in local awareness picked up after a few international newspapers, such as New York Times, have publicized the sad state of affairs on their front pages and Indian think tanks, such as Centre for Science and Environment, issued detailed assessment reports. So, after years of lethargy on the issue, we are living historical times this week:

• 6 April – release of the much-awaited national Air Quality Index (AQI);
• 7 April – Ministry of Environment (MoE) and Central Pollution Control Board (CPCB) have 15 days to develop rules on handling construction dust and waste;
• 8 April – the National Green Tribunal banned most polluting vehicles from Delhi (see article). Decision was to enter into force in..20 hours!

Let’s carry on at this pace – not that implementation challenges won’t come up, but what a step forward!