Bad air day: Indian city chokes on world's worst pollution

Hospitals say they have seen a rise in the number of patients with breathing-related problems. [Chandan Khanna, AFP]

Soot turned the white handkerchief around Abhash Kumar Sharma's face to black as the police officer tried to direct gridlocked traffic in the Indian city with the world's dirtiest air.

It was all he had to ward off the pollution blamed for filling Kanpur's hospital beds with growing numbers of chronic lung and cancer cases.