New Delhi: Wind directions changed by Tuesday noon, creating an outlet for the toxic air over the Delhi-NCR region and thereby improving the air quality to "very poor," from "severe" in the morning and "emergency" a day before. However, a threat of air quality reverting to "severe-plus" looms, depending on the weather conditions and how the Delhi-NCR celebrates its Diwali.
Coarser and highly dangerous PM2.5 or particles with a diameter less than 2.5 mm continue to dominate the pollution factor in Delhi and are still at least four times higher than the national standards and nine times the international standards. PM2.5 levels are expected to spike, bringing the region's air quality back to "emergency" for two days -- November 8 and 9 -- if Delhi bursts even 50 per cent of firecrackers that it did on last year's Diwali, warns System of Air Quality and Weather Forecasting And Research (SAFAR). (IANS)