Air quality ‘severe’ for sixth day in Noida, Ghaziabad

Noida: The air quality of Noida, Ghaziabad and Greater Noida on Tuesday continued to reel under ‘severe’ category for the sixth day in a row, witnessing one of the

Noida: The air quality of Noida, Ghaziabad and Greater Noida on Tuesday continued to reel under ‘severe’ category for the sixth day in a row, witnessing one of the worst pre-Diwali air pollution scenario in the three cities.

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On Tuesday, Noida’s air quality saw a marginal improvement, but the pollution levels remained well within ‘severe’ category, with average PM2.5 levels for the city was nine times higher than the standard limits.

According to the Central Pollution Control Board (CPCB) data, the air quality index (AQI) of Noida, on a scale of 0 to 500, on Tuesday was 455 against 477 a day earlier. The AQI value of Greater Noida was 436 against 478 a day earlier, while AQI of Ghaziabad was 444 against 482 a day earlier.

However, officials of the India Meteorological Department (IMD) said that the meteorological conditions are likely to get better as wind directions on Tuesday noon changed from north-westerly to easterly and are picking up speed bringing a ray of hope that the trapped pollutants would start ventilating out in the next two days.

“The wind directions have changed from north-westerly which is from the direction of Punjab and Haryana to the easterly. So, the current winds entering Noida, Ghaziabad and then Delhi are from the direction of Uttar Pradesh. By Wednesday, the easterly winds may increase to 10-12 kmph which may help improve the air quality a little by stopping extra stubble burning smoke entering the region and ventilating the pollutants out,” said Kuldeep Srivastava, head, regional weather forecasting centre, IMD.

However, IMD said that the moisture in the air is also high with air having around 50% moisture content during afternoon hour and by the evening it increases to 90%.

Experts said that due to the high moisture content, the air traps pollutants making ventilation difficult.

“During winter when the air is heavy due to the moisture, the particles or aerosols get heavy as well or trapped and they get close to the ground. This worsens the situation as the pollution levels accumulate at lower height. Also, more wind speed is required to ventilate them,” said Shambhavi Shukla, programme officer (air pollution), Centre for Science and Environment (CSE).

So far the local source of pollution, including construction, vehicular emissions and the smoke from stubble burning in neighbouring states brought along with north-westerly winds have made the region suffer a severe air quality since November 5.

On Tuesday, the average PM2.5 levels for Noida for the past 24 hours was recorded at 547.99 microgrammes per cubic metres (ug/m3), while for Greater Noida it was 536.87 ug/m3. The average PM10 levels for Noida was 619.51 ug/m3, while for Greater Noida it was 661.49 ug/m3.

As per CPCB, the PM2.5 and PM10 safe limit is 60 and 100 ug/m3, respectively.