Delhi’s yearly nightmare begins as air quality dips

Weather, stubble burning are contributing to mess

NEWDELHI: POLLUTION levels in the national capital and neighbouring cities shot up again on Saturday as the wind speed dropped to zero, trapping local pollutants, including vehicular emissions and road dust, in the air, even as the first effects of farm fires started to be felt.

A thick haze hung over the city in the early part of the day and eight monitoring stations out of the 36 recorded ‘very poor’ levels of air quality – a stark contrast from the day before when air quality was ‘moderate’ as the city recorded strong, cold winds.

The overall Air Quality Index (AQI) in Delhi was classified as poor at 262 on Saturday – a day before it was 154 and in the moderate category, according to the Central Pollution Control Board (CPCB).

Levels of PM2.5, combustion particles that are roughly forty times finer than the average human hair, more than doubled in the last couple of days.

A key source of PM2.5 at this time of the year is the fires farmers in neighbouring Punjab and Haryana light to clear their fields of paddy residue after harvesting their paddy crop.

In the coming days, officials expect a combination of three factors to drastically worsen the pollution: wind speed is likely to remain low, local emissions are set to increase because of the festive rush and pollutants from more farm fires are expected to drift in, said D Saha, former head of CPCB’S air quality lab.

The other major pollutant, PM10, also rose to 289.7 micrograms/cubic meter – nearly thrice the 100 microgram/cubic meter level that is considered safe. On Thursday, the India Metrological Department (IMD’S) informed the CPCB that the wind direction will change to north-northwest from Friday onwards, meaning that pollutants will start drifting into the capital from Punjab, and even beyond, from Pakistan.