Delhi's air quality oscillated between 'very poor' and 'severe' on the first day of 2019 as authorities said the pollution level was reducing despite adverse weather conditions, suggesting no additional emissions were added on New Year's Eve.

The Centre-run System of Air Quality and Weather Forecasting (SAFAR) on Monday warned that any new trigger, particularly due to "open fire and pyrotechnic display", will make the air heavier and thicker which may lead to rapid deterioration in air quality to a severe-plus range.

According to the Central Pollution Control Board (CPCB) data, the overall air quality index (AQI) in the city on New Year's Day was 393, which falls under 'very poor' category, while the SAFAR recorded an AQI of 402, which falls under the 'severe' category.

Even as the national capital continued its battle with toxic air, several instances of firecracker bursting, before and after the time limit fixed by the apex court, were observed in Delhi-NCR during New Year celebrations.

The CPCB had earlier written to the Delhi Police and district magistrates of the national capital, Noida and Gurgaon ahead of Christmas and New Year's Eve to ensure that the Supreme Court order in this regard is followed and no firecrackers are burst.

The court had said that on Christmas and New Year's Eve, green firecrackers would be allowed to be burst between 11.55 pm and 12.30 am since these celebrations start midnight.

'Severe' pollution was recorded in 16 areas in Delhi, while 'very poor' in 18, the CPCB data showed. Air quality in Ghaziabad and Noida was 'severe', while 'very poor' in Faridabad and Gurgaon.

The overall PM2.5 level (fine particulate matter in the air with a diameter of less than 2.5 micrometers) in Delhi was recorded at 267 and the PM10 level at 437, the CPCB said.

Delhi Environment Minister Imran Hussain has directed immediate closure of three concrete mixing plants for allegedly failing to comply with dust control norms contributing to air pollution in the national capital, an official statement said.

"There were no sprinkling arrangements at the site, cement was not covered by any sheets, as required, and the approach road was blanketed by dust," it said.

The SAFAR said the air quality of Delhi was improving slowly in spite of adverse weather conditions.

"This tends to suggest that no additional emissions are added last night. Moderate wind speed during the day is dispersing pollutants and the AQI is likely to improve but no significant improvement is expected as winds are likely to be calm at any time in the prevailing sensitive environment," it said.

It said the moisture-laden wind speed from the west is likely to cover most part of Delhi by Wednesday and foggy conditions are likely to prevail. Air quality is expected to remain 'very poor' for the next three days.

Delhi has been battling alarming pollution levels since October. In the last 10 days, the city has witnessed long spells of severe air quality which continued to plague the city on New Year's Eve and on the first day of 2019.

(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)