After showing a decline in Diwali in 2017, air pollution doubled this year in most regions of Delhi. However, it is better than 2016 when air quality was worst in the national capital. The Central Pollution Control Board (CPCB) data suggests that particulate matter (PM) 2.5 \u2014 particles in the air with a diameter of less than 2.5 micrometres \u2014 has roughly doubled this year on Diwali from 180 to 322, and PM 10 is slightly more than what it was in 2017. A major change has been recorded in PM 2.5. A day after Diwali, Delhi's average Air Quality Index was found to be in 'very poor level'. The pollution board on Thursday said that the severe decline in air quality this year was due to unfavourable conditions coupled with pollutants stemming from firecrackers. It also observed that meteorology and stubble burning make a huge difference in the national capital's air quality in late October and November. Last year, Diwali was observed in October but this year, the festival was celebrated in November. According to the CPCB, November has different meteorological conditions that govern the dispersion pattern of pollutants. "This year, Diwali day shows that the PM10 and PM2.5 values have increased this year compared to 2017. However, the data are similar to Diwali day of 2016 which was observed on October 30," the CPCB said. The pollution agency put out a break up of different areas and said that in Pitampura, the PM 10 level was 831 and PM 2.5 level was 990 in 2018. However, the same was recorded at 677 and 690 respectively last year. In Janakpuri, the PM10 and PM2.5 levels were 1076 and 998, while it was recorded at 706 and 638 respectively last year. According to System of Air Quality and Weather Forecasting and Research (SAFAR) report, the overall AQI on Thursday was recorded in the "severe plus emergency" category at 642. Last year, the AQI was recorded at 367, while it was 425 in 2016. This year, the AQI was double that of last year. SAFAR in its advisory claims that a "severe plus emergency" AQI means that even healthy people may suffer from respiratory illnesses on prolonged exposure. Keeping Delhi pollution in mind, the Supreme Court had this year restricted the bursting of firecrackers during Diwali. It had allowed only green crackers and that too for two hours between 8 pm and 10 pm. However, the top court order was violated in many cities including Delhi where people kept bursting crackers till late Wednesday night. According to PTI, the areas where the violations were recorded are Mayur Vihar Extension, Lutyens' Delhi, Lajpat Nagar, IP extension, Dwarka and Noida Sector 78. The Delhi Police arrested 310 people and registered 579 FIRs against those who violated the Supreme Court order.\u00a0Similar actions were taken in other cities too. According to PTI, Tamil Nadu registered 2,190 cases for violating the top court order. In Telangana, 75 cases were filed in Hyderabad while in Puducherry, around 30 cases were registered for flouting\u00a0the two-hour window set by the SC.