NEW DELHI, Nov 13 (Reuters) - Two Indian cities joined New Delhi to be among the world's worst 10 for pollution on Monday morning, with smoke heavy in the air a day after revellers let loose with firecrackers for Diwali - the annual Hindu festival of light.
It had an air quality index (AQI) figure of 420, putting it the 'hazardous' category, according to Swiss group IQAir.
An AQI level of 400-500 impacts healthy people and is dangerous to those with existing diseases, while a level of 150-200 brings discomfort to people with asthma, lung and heart problems.
Every year authorities impose bans on firecrackers in the capital, but only rarely do those bans appear to be enforced.
Air quality in India deteriorates every year ahead of winter, when cold air traps pollutants from vehicles, industry, construction dust and agricultural waste burning.
Persons:
Tanvi Mehta, Edwina Gibbs
Organizations:
Thomson
Locations:
DELHI, New Delhi, Swiss, Kolkata, India's, Mumbai, India