How to dodge air pollution while crossing a city
Air pollution kills more than five million people every year. Many of those deaths occur in towns and cities where for the first time in history more than half the world's population now live.
Hong Kong is one of the most polluted cities in the world, with three times as many air pollutants as New York.
Ayan Panja travelled there to find out which was the safest way to cross the city.
28 Mar 2016