Rain steps in to clear the air in Noida and Ghaziabad, AQI improves by several points

The picture was vastly different on Thursday before the rain came. Greater Noida was the most polluted city in the country that day with an AQI of 439, in the “severe” category, while Ghaziabad recorded an AQI of 391 (very poor) and Greater Noida an AQI of 394

The light, scattered rain since Thursday night helped bring down pollution levels in Noida and Ghaziabad on Friday ahead of Diwali festival, which has been witnessing an air quality in the “severe” category for more than a week.

Although the scattered and light rain continued in short spells though Friday as well, a steeper dip in AQI did not occur, said weather scientists. (Sunil Ghosh/HT Photo)

According to the daily air quality index (AQI) bulletin of the Central Pollution Control Board (CPCB), Greater Noida recorded an AQI of 272 on Friday, followed by Ghaziabad with an AQI of 267, and Noida with an AQI of 247, all values in the “poor” category.

The picture was vastly different on Thursday before the rain came. Greater Noida was the most polluted city in the country that day with an AQI of 439, in the “severe” category, while Ghaziabad recorded an AQI of 391 (very poor) and Greater Noida an AQI of 394.

According to the AQI scale, readings between 0 and 50 are considered “good”, 51 and 100 are “satisfactory”, 101 and 200 are “moderate”, 201 and 300 are “poor”, 301 and 400 are “very poor”, and 401 and 500 are “severe”.

The primary pollutant in Ghaziabad and Greater Noida was PM2.5 while Noida was affected by higher PM10 levels on Friday.

Although the scattered and light rain continued in short spells though Friday as well, a steeper dip in AQI did not occur, said weather scientists.

“As an effect of light rainfall in the region, the AQI levels have come down a bit. It is so as the average AQI is calculated from 4pm on Thursday till 4pm on Friday, in the CPCB index. So, the AQI figures for Saturday are expected to be much lower owing to the rainfall activity.We expect the AQI to remain around 200 on Saturday. The wind speed has also picked up, which will favour dispersal of pollutants. A cleaner Diwali festival is on the cards,” said Utsav Sharma, regional officer, UPPCB, Noida.

The officials of the India Meteorological Department (IMD) said on Friday that the rainfall activity was the result of a a western disturbance (WD).

“Under the influence of the WD, rainfall activity is likely to continue over north west India... the WD has caused light to moderate rainfall over Jammu and Kashmir and isolated areas of Himachal Pradesh, and parts of Uttarakhand. Also, scattered and light to moderate rain was witnessed in Punjab, Haryana, Delhi and adjoining parts of western Uttar Pradesh. The activity is likely to continue for the next 12 to 24 hours,” the IMD said in its forecast on Friday.

Akash Vashishtha, an environment lawyer, said, “The rain has provided much needed relief, otherwise the AQI levels were ranging between ”very poor” and ”severe”. However, use of firecrackers, and heavy traffic movement during the festival days may likely lead to a rise in pollution before and after Diwali festival. The rainfall in parts of Punjab may have also brought down instances of stubble burning.”

According to the data compiled by the Consortium for Research on Agroecosystem Monitoring and Modelling from Space (CREAMS) laboratory of the Indian Agricultural Research Institute, New Delhi, the state of Punjab witnessed 23,620 instances of residue burning between September 15 and November 9.

Haryana, during the same period, saw 1,676 instances of stubble burning, Uttar Pradesh 1,503, Madhya Pradesh 7,383, and Rajasthan 1,164.

The figure for Uttar Pradesh include 19 instances of stubble burning in Ghaziabad and nine in Gautam Budh Nagar.

According to forecast by the ”Air quality early warning system for Delhi”, the air quality is likely to be improve and will reach ”poor” category on November 11. “The air quality is likely to deteriorate and will reach ”very poor” category on November 12 and “severe” category on November 13. The outlook for subsequent six days: The air quality is likely to remain in ”severe” to ”very poor” category,” the forecast said on Friday.