Light showers bring no respite, take Delhi’s toxic smog to season’s worst
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Environment

Light showers bring no respite, take Delhi’s toxic smog to season’s worst

While SAFAR recorded an AQI of 650 at 11 am Sunday, CPCB, another govt monitor, estimated it at 428 at 10 am.

Mohana Basu    
Delhi smog

India Gate is eclipsed by smog in Delhi (representational image)| Photo: Suraj Singh Bisht | ThePrint

New Delhi: Light showers in parts of Delhi Saturday night had raised hopes that pollution levels will drop, but residents woke up to worsening smog Sunday, as air quality dipped to the season’s lowest.

The air quality index (AQI) was recorded at an alarming 650 at around 11 am by one of the two government pollution monitors, SAFAR or System of Air Quality and Weather Forecasting And Research.

The Central Pollution Control Board (CPCB), another government monitor, showed the AQI at 428 around 10 am Sunday, while numerous independent agencies showed readings of over 900, raising questions over whether government agencies were presenting an accurate picture of air quality in Delhi. To throw the capital’s situation in stark relief, an AQI of up to 200 is considered moderate.

“The unexpected light drizzling last night in a calm wind condition worked highly adversely in deteriorating air quality and season’s highest level of AQI (air quality index) of PM2.5 is recorded today as rapid secondary aerosol formation started in the wee hours,” SAFAR reported. 

The drizzle Saturday night increased humidity, which in turn bolstered the atmosphere’s capacity to hold pollutants. 

It also brought down the mixing layer height to the season’s lowest (~50 metres), which further aggravated Delhi’s continuing smog crisis. The mixing layer height is the height at which pollutants can disperse — the higher this height, the less the effects of pollutants.

Also Read: Amar Ujala blames govts for Delhi smog, Dainik Bhaskar says Centre should spend on health

Political slugfest over pollution

Delhiites took to Twitter Sunday morning to share photos of the haze, which reduced visibility to near-zero at many places, and the worrying readings made by their personal air quality monitoring devices even indoors.

 

News agency PTI reported that 32 flights had been diverted from the Delhi airport since the morning due to low visibility.

After claiming that pollution levels in Delhi had come down by 25 per cent because of their efforts, politicians from both the BJP and the AAP took to Twitter to criticise each other.

 

Environmentalist Chandra Bhushan told ThePrint that the claim of reduced air pollution in Delhi was baseless.

“I have looked at the CPCB data myself and there is no evidence that the pollution is decreasing. In fact, it has been increasing over the last few years,” said Bhushan, who has worked in environmental research for over 25 years.

He also said there was no point taking credit for a slight improvement in air quality when pollution is almost 10 times worse than what is acceptable.

“Such small decreases have no overall benefit on the health burden caused by pollution,” he said.

Stubble fires down?

Meanwhile, SAFAR said a drastic reduction was recorded in the number of stubble fires — believed to be one of the primary drivers of smog — in Haryana & Punjab over the last 24 hours (57). 

However, a dense cloud cover over the region may have obscured active fire detections by satellite, the agency added. 

The agency said such a rapid build-up of pollutants does not last long and Delhi is likely to recover by late evening Sunday as heat from sunlight causes pollutants to rise up. 

The AQI is expected to remain in the ‘severe’ category until early Monday, but start recovering thereafter.

Also Read: Delhi’s air pollution masks a class war that nobody is willing to talk about