Why India’s numbers on air quality cannot be trusted

For some time now, India has been putting out her air quality numbers. Visit the website of the Central Pollution Control Board (CPCB) or the State Pollution Control Boards (SPCBs) and you will find them. In the odd city, you will see LED displays giving real-time updates on air quality in the city. How accurate are these numbers?

Not very. To know why, click here. A PDF of the superb page my colleagues designed. And here, a link to the story.