New Delhi residents are suffocating only to find little to no relief. The city, as well as much of Northern India, home of over 400 million people, is blanketed by a thick layer of smog. The air quality has severely depreciated, hitting alarming 1,000 AQI PM2.5 level -- over 15 times of the safe limit. The air quality index hasn't gone down 400 reading, which is considered hazardous. From a report on CNN: Measurements taken at the US Embassy in Delhi put the city's Air Quality Index at 999 on Monday, off the standard chart, which finishes at the "hazardous" level of 500. By comparison, the highest AQI level recorded Monday in Baoding -- China's most polluted city -- was 298. Beijing was a pleasant 30, while India's next most polluted city, coal and industry-heavy Chandrapur, recorded levels of 824, according to the World Air Quality Index. Research released earlier this year found that air quality levels exceed World Health Organizations guidelines for 80% of those living in urban areas around the world.Though Delhi has been one of the most polluted cities for decades, burning of tens of millions of crop stubbles in the recent months and the Hindu festival of Diwali (which sees many people set off fireworks) have been held responsible for the severe air quality.