An urban guide to surviving the winter pollution

Pollution at severe levels in major cities is putting lives at risk. What can you do to protect yourself?

The Delhi government recently volunteered to pay for helicopters that will sprinkle water over the city to settle the dust and reduce the level of pollutants (particulate matter, or PM) in the air.

But environmentalists and air quality experts have junked the idea. At the time of writing this article, the maximum PM 2.5 and PM 10 levels in Delhi were above 350 and 450 — the safe limits are 60 and 100, respectively.

Smog makes our bodies more acidic

At present, Delhi air is categorised at