"Pollution has become a very risky issue.Toxic air is causing health hazards for both adults and children.In view of the falling standard of air quality, the CPCB has issued an advisory.it is very shameful that despite being the capital of the country, Delhi is the most polluted State", Mr. Tiwari said. Of the 67 cities where the air quality was monitored, 17, including Patna, recorded "very poor" air quality.
Experts said though showers normally disperse the pollutants, paving way for plunge in the AQI, the air quality could not improve in Patna which received just 1.1mm of rainfall between Monday night and Tuesday morning.
In view of prevalence of "severe" pollution in the national capital, industrial activities in pollution hotspots of Wazirpur, Mundka, Narela, Bawana, Sahibabad and Faridabad, and construction work across Delhi-NCR was ordered to remain shut till Wednesday.
CPCB Chairman S P Singh Parihar, who was also present at the press conference, said December 26 onwards the winds are expected to pick up speed, which is likely to bring down the pollution levels. "We have already sanctioned metro Phase-IV and a project to revive 159 lakes to increase the green cover", he added.
"The wind speed and ventilation index are highly unfavourable for dispersion of pollutants", it said. However, System of Air Quality and Weather Forecasting And Research (SAFAR), recorded the overall AQI at 477.
The AQI recorded 217 with PM (particulate matter) 2.5 at 557 and PM (particular matter) 10 at 747.
Ventilation index is the speed at which pollutants can get dispersed.
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After four consecutive days of "severe" air pollution, Delhi's air quality improved to "very poor" and according to the weatherman, it is likely to remain in the same zone for the next three days, with dense fog engulfing the city.
The task force also urged people to avoid using private vehicles, particularly those using diesel as fuel, and minimise outdoor exposure for the next three to five days, especially those with respiratory illness, the CPCB said.
Senior government officials said the main reasons for the surge in the amount of toxic smog trapped over New Delhi were unusually cold air, including fog, and a lack of wind.
The agency has advised Delhiites to avoid all outdoor activities, such as taking walks.
At 4 p.m. on Monday, the Air Quality Index (AQI) was recorded at 448.
Officials said they are closely monitoring the situation and if these conditions persist for 48 hours, then stringent action would be taken.