Delhi's air quality remained in the 'severe' category for the fourth consecutive day on Tuesday as meteorological conditions continued to be unfavourable for dispersion of pollutants, authorities said.
The city is facing its worst pollution crisis since Diwali. While the Central Pollution Control Board (CPCB) data showed the overall air quality index (AQI) at the 'severe' level of 416, the Centre-run System of Air Quality and Weather Forecasting (SAFAR) recorded an AQI of 423. Twenty-five areas recorded severe pollution levels, while nine others recorded very poor air quality, the CPCB data showed. In the NCR, Faridabad, Ghaziabad and Noida recorded severe pollution while Gurgaon recorded 'very poor' quality air. The national capital recorded its second highest pollution level of the year on Sunday with an AQI of 450. According to the SAFAR, the overall air quality in Delhi is expected to remain in the 'severe' range till Tuesday.
"Recovery got delayed mainly due to the slowing of wind speed, leading to persistence of fog which rapidly multiplied finer particles, leading to rapid increase in PM2.5 and even PM1 (fine particulate matter in the air with a diameter of less than 1 micrometre)," it said. "Improvement is expected from late Tuesday evening only when the radiation fog gets dissipated with sufficient sunshine," it added.
According to the Indian Institute of Tropical Meteorology (IITM), air quality is likely to improve on Tuesday, but will remain in the upper end of the 'very poor' or in the 'severe' category. "The wind speed and ventilation index are highly unfavourable for dispersion of pollutants," it said. For those unfamiliar with the meteorological terminology, ventilation index is the speed at which the present pollutants can get dispersed. A ventilation index lower than 6,000 sqm/second, with average wind speed less than 10 kmph, is unfavourable for dispersion of pollutants. The index on Tuesday was 5,000 sqm/second on Tuesday, the IITM said.
In view of the prevalence of severe pollution levels in the national capital, industrial activities in the pollution hotspots of Wazirpur, Mundka, Narela, Bawana, Sahibabad and Faridabad, and construction work across the Delhi-NCR will remain shut till Wednesday, EPCA Chairperson Bhure Lal said. The Environment Pollution Control and Prevention Authority (EPCA) has directed traffic police to deploy special teams and ensure congestion-free vehicular movement, particularly in identified high traffic corridors.
The agencies concerned have also been asked to ensure strict action against illegal industries and make all efforts to control polluting activities, particularly waste burning. In a health advisory, the SAFAR has asked Delhiites not to rely on common dust masks for protection. The agency has also advised people to avoid all outdoor activities, such as taking walks.
