New Delhi, Oct 26 The air quality of the national capital and regions around it dropped severely, with Friday recording worse pollution than what it was a day after Dussehera.The Air Qaulity Index (AQI) of Delhi was recorded was 361, against 331 on Thursday and 326 a day after Dussehera, all recorded "very-poor", according to the Central Pollution Control Board (CPCB).With more regions now suffering a "severe or severe-plus" air-quality, the top four most polluted regions in Delhi included Jahangirpuri in north Delhi (AQI 464) and Mundaka in west-Delhi (AQI 444), Dwarka sub-city in south-Delhi (AQI 436), Anand Vihar in east-Delhi (AQI 415) -- all marked "severe".PM2.5 and PM10 or particles with diameter less than 2.5mm and 10mm, remained the major pollutant throughout the region, due to local factors such as vehicles, industries and dust and stubble burning in Punjab and Haryana.The average concentration of PM2.5 and PM10 across 36 region of Delhi was 207 and 405 microgrammes per cubic meters respectively, at 6 pm. A day after Dussehera, when pollution was recorded the highest last time due to Ravana effigy burning and festival rush, the average concentration of PM2.5 and PM10 at 6 pm was 181 and 388 units.Across 48 regions in NCR on Friday, the PM2.5 and PM10 concentration was 198 and 384 units, while on Dussehera, concentrations across NCR were 181 and 388 units."The winds are mostly calm and directions are indefinite around Delhi due to two different western disturbances. Due to this the pollutants are not dispersing," said Mahesh Palawat, director private weather forecasting agency Skymet.According to Central Pollution Control Board (CPCB), the situation is not set to change any sooner, while it may only get worse towards Diwali."There were north-westerly winds for sometime towards afternoon on Friday, apart from that the fire at landfill site at Bhalaswa which was only doused yesterday evening, may have their effect over Delhi's air," Shambhavi Shukla, researcher at CSE told IANS.