Delhi’s pollution turns ‘severe’ as temperatures, wind speeds drop

NEW DELHI – Air pollution in India’s capital increased to “severe” on an official index on Nov 13 for the first time this season as temperatures and wind speeds dropped, reducing visibility and affecting some flights.

Delhi overtook Pakistan’s Lahore as the world’s most polluted city in Swiss group IQAir’s live rankings, and India’s pollution control authority said the national capital territory’s 24-hour air quality index (AQI) score had touched 418.

The Central Pollution Control Board defines an AQI reading of zero to 50 as “good”, and above 401 as “severe”, which affects healthy people and “seriously impacts” those with existing diseases.

The Indian capital battles smog – a toxic mix of smoke and fog – every winter as cold air traps dust, emissions and smoke from illegal farm fires.

The authorities have on occasion closed schools, stopped some building work, and placed restrictions on private vehicles to curb the problem.

Pakistan’s Punjab province, which shares a border with India and is also battling toxic air, has in November banned outdoor activities, closed schools and ordered some shops, markets, and malls to close early.

The concentration of PM2.5 – particulate matter measuring 2.5 microns or less in diameter that can be carried into lungs, causing deadly diseases and cardiac issues – in Delhi was more than 120 times the World Health Organisation’s recommended levels in the morning on Nov 13, IQAir said.

Weather department officials also blamed the smog, which reduced visibility to zero in some places, on high humidity, low wind speed, and the minimum temperature dropping to 17 deg C from 17.9 deg C a day before.

At least eight flights were diverted from the city’s Indira Gandhi International Airport, news agency ANI reported.

Dense fog – defined as that which reduces visibility to 50m to 200m – was expected to continue over north-west India for the “next two to three days”, the India Meteorological Department said. REUTERS