NEW DELHI: Delhi’s air quality recorded “severe” levels on Saturday, a day before Diwali . A pall of smog was hanging over the city since morning.As forecast by IMD and SAFAR, the wind speed was very low, touching zero at times, which caused pollutants to accumulate very close to the surface. The Delhi government, meanwhile, blamed the high pollution levels on the farm stubble burning in Punjab and Haryana. On Saturday, it shared a NASA image from October 26 showing crop fires in these states.“Agricultural fires in the fields of neighbouring states, particularly Punjab and Haryana, are a major contributor in the deterioration of ambient air quality, which will accentuate due to inversion and calm meteorological conditions currently prevailing,” a Delhi government statement said. Environment minister Imran Hussain reiterated his appeal to the residents to stay away from crackers on Diwali. The government had seized illegally-imported crackers at Qutab Roa, Moti Nagar, Rajouri Garden and Patel Nagar recently.This is the first time this season that the overall AQI (Air Quality Index) for the city recorded severe. A pollution emergency occurs when AQI is severe—even healthy people can be affected by such high levels of PM 2.5 (fine, respirable pollution particles). It can seriously affect those with existing health conditions.A 24-hour average pre-Diwali monitoring for three residential areas—RK Puram, Mandir Marg and Punjabi Bagh between 6am on October 28 and 6 am on October 29—showed the PM 2.5 average to be higher than 250 micrograms per cubic metres at RK Puram and Punjabi Bagh, more than four times the national safe standard and 10 times the WHO benchmark. The PM 10 average was 543 at RK Puram, which is five times the national safe standard and about 10 times the WHO cut-off mark.“IMD had forecast that wind speed is going to drop and SAFAR had predicted air quality will be severe. The government should have issued a health advisory, urging people not to burn any crackers. Soft messages don’t work,” said Anumita Roy Chowdhury, head of CSE’s clean air campaign. “There is enough evidence now that such high levels of pollution aggravate existing conditions and trigger heart attacks, strokes and other respiratory issues. In fact, pollution is responsible for more than 50% of heart attack cases.”SAFAR advised people to avoid all outdoor physical activity. People with heart or lung disease, older adults, and children should remain indoors and keep activity levels low, it said."There is health warning for emergency conditions and serious risk of respiratory effects in general public," it said.The health ministry’s steering committee report on air pollution lists mortality due to cardiovascular and respiratory disease, chronic respiratory disease incidence (asthma, COPD, etc), lung cancer, chronic cardiovascular disease, among others as a result of long-term exposure to high levels of pollution.If AQI continues to be severe for the next couple of days, it would fall below Beijing’s red alert category when the Chinese capital shuts schools and industries, reduces power plant emissions and restricts car usage.