A thick cloud of toxic smog nearly 10 times the recommended limit continued to envelop Delhi on Friday as the air quality deteriorated and was. recorded under ‘hazardous’ category.

The overall Air Quality Index (AQI) of Delhi at 8:15 am was recorded at 428, which falls under the hazardous category, according to System of Air Quality and Weather Forecasting (SAFAR) the autonomous meteorological body set up under the Union ministry of earth sciences.

An AQI between 0-50 is considered good, 51-100 is satisfactory, 101-200 moderate, 201-300 poor, 301-400 very poor and 401-500 is marked as severe/hazardous.

According to news agency ANI, AQI was 724 in Dhirpur at 8:30am and it dipped to ‘very poor’ category at 625 in Mathura Road area. AQI near Pitampura, Airport, Terminal 3 and Delhi University stood at 679, 481 and 801 respectively.

On Friday, the humidity level in Delhi was 100% with visibility 0.5 miles.

The haze and smog will continue to persist during the early morning and late evenings for the next couple of days.

A report by a research group Urban Emissions said that as much as 5 million kilograms of firecrackers were burnt in the region leading to an emission of 150,000 kilograms of Particulate Matter (PM) 2.5 despite the Supreme Court’s order stating that bursting of firecrackers will be allowed only for two hours on Diwali.

Experts say replacement of moderate winds with light and calm winds, low temperatures, increased humidity levels along with the burning of crackers has been responsible for the deteriorating air quality and also contributing in increasing the toxicity in the air.

A day after Diwali on Thursday, Delhi was engulfed in a haze in the morning as residents celebrated the festival by bursting firecrackers despite the Supreme Court order against polluting fireworks, pushing up levels of harmful particulates to emergency levels.

Even though the Air Quality Index (AQI) value was recorded to be 350, which indicates very poor levels of air pollution, the level of PM2.5 shot up to the emergency levels to at least 6.3 times above the safe standards. The ultra-fine PM 2.5 airborne particles, about 30 times finer than a human hair, can be inhaled deep into the lungs, causing respiratory diseases and other ailments.

The Supreme Court had allowed bursting firecrackers only for two hours on Diwali in Delhi and the National Capital Region (NCR) and permitted manufacturing and sale of only “green crackers” with low emission of light, sound and smoke.

Senior Delhi Police officials admitted “sporadic” breaches of the top court’s order on bursting crackers beyond the 8pm to 10pm time frame fixed by it.

Government agencies such as SAFAR had predicted Delhi could encounter severe levels of pollution from November 8 even if 50% of the firecrackers as compared to 2017 were burst this year.

Scientists had also forecast that the pollution would linger over the next two days till November 10, as weather conditions would be unfavourable. They said Delhi would face the impact of stubble burning from November 8 as weather conditions would become adverse.

Delhi, a city of nearly 16 million, recorded its worst air quality of the season on Monday, when the pollution levels were eight times the permissible limit as a thick haze engulfed the city.

Doctors have said the impact of air pollution on public health can be compared to smoking 15-20 cigarettes a day.

Delhi had seen the worst smog in 17 years in 2016 during the post-Diwali period. In 2017, there was a ban on the sale of crackers but Delhi still witnessed a very poor air quality a day after Diwali.

(With agency inputs)

First Published: Nov 09, 2018 10:54 IST