Wind, thinning fog push Delhi air quality into 'very poor'€™ category

New Delhi, Dec 17 (PTI) Delhi saw a marginal improvement in air quality on Tuesday as stronger winds and thinning fog pushed pollution levels out of the 'severe' category after three days, though they were still in the 'very poor' range.

Delhi's 24-hour average Air Quality Index (AQI) stood at 354 at 4 pm, according to the Central Pollution Control Board (CPCB).

Of the 39 active air quality monitoring stations in Delhi, only Mundka was in the 'severe' category with an AQI of 407, while 35 stations recorded 'very poor' air and three 'poor' air.

Institute of Human Behaviour and Allied Sciences (IHBAS) in Dilshad Garden recorded the lowest AQI of 280, at the higher end of the 'poor' range, according to the CPCB's Sameer app.

According to the CPCB, an AQI between 0 and 50 is considered 'good', 51 to 100 'satisfactory', 101 to 200 'moderate', 201 to 300 'poor', 301 to 400 'very poor', and 401 to 500 'severe'.

Data from the Decision Support System for Air Quality Management in Delhi showed that transport contributed 11.95 per cent to the city's pollution on Tuesday.

Neighbouring Jhajjar contributed 11.9 per cent, construction activities 1.62 per cent, and other sources together contributed the largest share at 51.7 per cent. On Wednesday, transport emissions are projected to rise to 16.2 per cent.

According to the India Meteorological Department (IMD), Delhi witnessed shallow fog on Tuesday, marking a shift from the very dense fog recorded a day earlier.

Palam reported the lowest visibility of 600 metres at 8 am, followed by 800 metres at Safdarjung.

An IMD official said Monday's dense fog across north India had a cascading impact on air traffic, affecting flight operations on Tuesday as well, even though visibility improved slightly in the capital.

Meteorological conditions played a key role in the improvement.

"Air quality improved due to strong westerly winds. Wind speed touched 18 to 20 kmph during the afternoon and remained mostly between 10 and 12 kmph during the day. Moderate to strong winds are expected to continue for the next two to three days, which may lead to further improvement," said Mahesh Palawat, Vice President, Skymet Meteorology.

The Centre's Air Quality Early Warning System (EWS) for Delhi, however, cautioned that the relief may be short-lived. The air quality is likely to remain in the 'very poor' category till Friday, while from December 19 onwards, it may fluctuate between 'very poor' and 'severe'.

Health experts warned that even short-term exposure to such pollution levels can have serious consequences, particularly for children.

Dr Medha, paediatrician at Madhukar Rainbow Children's Hospital, said rising air pollution poses a grave threat to infants, whose lungs and immune systems are still developing.

"Infants breathe faster and inhale more air in proportion to their body weight than adults, leading to higher exposure to pollutants like PM2.5, PM10, nitrogen dioxide, carbon monoxide and ozone. These particles can penetrate deep into the lungs and even enter the bloodstream," she said.

Dr Medha added that frequent exposure to polluted air is increasingly being linked to recurrent cough, wheezing, breathlessness and conditions such as bronchiolitis in infants.

"Continuous exposure also weakens their immune defences, making them more susceptible to colds, pneumonia and other respiratory infections," she said.

Delhi recorded a minimum temperature of 8.3 degrees Celsius, 0.3 degrees below normal, while the maximum temperature settled at 24.9 degrees Celsius, 1.9 degrees above normal, according to the IMD.

Humidity levels fluctuated between 76 and 100 per cent during the day.

The weather office has forecast moderate fog for Wednesday, with the maximum and minimum temperatures expected to settle around 23 degrees Celsius and 9 degrees Celsius, respectively. PTI NSM DIV DIV