Residents of Delhi breathed easy on Sunday after air quality significantly improved due to increased wind speed and control measures implemented by the Government. The overall air quality index (AQI) at 4 pm on Sunday was recorded at 171, which falls in the ‘moderate’ category. In the morning it was 231, which falls in the ‘poor’ category, said the Central Pollution Control Board (CPCB) data .
The improvement in air quality can be attributed to the increase in surface wind speed to five km per hour which flushed out pollutants, said an official of the Centre-run System of Air Quality Forecasting and Research (SAFAR). The reduction in base emission is also suggestive of more pronounced effect of control measures taken by authorities, the official said. On Friday, the AQI was 370, which came down to 336 on Saturday, according to the CPCB.
An AQI between 0 and 50 is considered ‘good’, 51 and 100 ‘satisfactory’, 101 and 200 ‘moderate’, 201 and 300 ‘poor’, 301 and 400 ‘very poor’ and 401 and 500 ‘severe’. It has been found that PM 2.5 emission reduced “from 432 ton per day to 370 ton per day to reproduce the observed level with realistic met parameters, a decline in base emission by 14 per cent in Delhi and nearby domain”, said the official.
PM 2.5 are particles in the air with a diameter of less than 2.5 micrometres. The SAFAR also said there is a large possibility of increase in moisture from Monday evening, which might lead to increase in the pollution level.
“The AQI is predicted to be in the lower range of very poor Monday as the atmosphere is relatively clean,” the official said. The Indian Institute of Tropical Meteorology (IITM) said fire counts in the northwest region of India were significantly less on Saturday as compared to Thursday, but warned of sharp increase in PM2.5 concentration from Monday.
“If significant stubble burning continues on Sunday and Monday in the NW (northwest) region of India then its impact is very likely over Delhi and AQI may reach the upper end of the very poor category.
“The northwest wind direction may bring influence of biomass fire on Tuesday and Wednesday,” the IITM said.
Authorities have attributed the improvement in air quality to control measures and meteorological conditions but they have also warned of deterioration of air quality to ‘severe’ levels from Monday.
There is a halt on all construction activities involving excavation. Civil construction has also been suspended in Delhi and other NCR districts, besides closure of all stone crushers and hot mix plants generating dust pollution.
Delhi authorities have stepped up efforts to combat pollution which includes measures like halting construction activities and regulating traffic. There is a halt on all construction activities involving excavation.
Civil construction has also been suspended in Delhi and beighbouring districts, besides closure of all stone crushers and hot mix plants generating dust pollution. The Delhi Pollution Control Committee (DPCC) has also directed the Transport Department and the Traffic Police to intensify checking of polluting vehicles and control travel congestion in the region during November 1-10.
An aggressive 10-day-long ‘Clean Air Campaign’ from November 1 to 10 has also been launched to monitor and report polluting activities as well as to ensure quick action.