Residents of every city in India can burst green crackers on Diwali if the ambient air quality remained better than the “poor” category, the Supreme Court said on Monday as it set aside a Calcutta high court order imposing a blanket ban on bursting of crackers and exceeded the previous SC order restraining use of hazardous fireworks that mostly use barium salts.Residents of every city in India can burst green crackers on Diwali if the ambient air quality remained better than the “poor” category, the Supreme Court said on Monday as it set aside a Calcutta high court order imposing a blanket ban on bursting of crackers and exceeded the previous SC order restraining use of hazardous fireworks that mostly use barium salts.