NOIDA/New DELHI, Dec. 20 -- An overly familiar and now-routine smog returned to the National Capital Region (NCR) on Friday, pushing the region to the top of India's pollution charts, with Noida, Greater Noida and Delhi emerging as the three most polluted cities in the country. According to the Central Pollution Control Board's (CPCB) daily bulletin, seven of the 10 most polluted cities in India on Friday were located in NCR, underscoring the scale and persistence of the air quality crisis gripping the region as winter conditions tighten their hold. Noida topped the national list with an air quality index (AQI) of 410, firmly in the "severe" zone. Greater Noida followed with an AQI of 376, while Delhi ranked third with a 24-hour average AQI of 374, both categorised as "very poor". Ghaziabad stood fourth with an AQI of 358. Dharuhera in Haryana was sixth at 332, Ballabhgarh near Faridabad seventh at 324, and Gurugram eighth at 322. If things weren't already bad, the forecasts suggest that it may get even worse. According to India Meteorological Department (IMD)'s forecast air quality may slip into the "severe" category in Delhi by the end of the week. Meteorologists said the sharp deterioration was driven largely by dense fog and stagnant atmospheric conditions that have severely restricted the dispersion of pollutants. Mahesh Palawat, vice president (meteorology and climate change) at Skymet Weather, said dense fog set in on December 18 and intensified through Friday. "Temperatures remain low, skies are clear, winds are light and variable, and humidity levels are high during night and early morning hours. These are ideal conditions for dense fog formation," he said. In Delhi, pollution levels were severe across most of the city. Of the 40 active air quality monitoring stations, 33 recorded 'very poor' air and six recorded 'severe' levels on Friday evening. Anand Vihar recorded the worst readings, with an AQI of 430 at 4pm, followed by Vivek Vihar (423), ITO (421), RK Puram (417), Siri Fort (417) and Nehru Nagar (415). Data from the Centre's Decision Support System (DSS) for Air Quality Management showed vehicular emissions continued to be a major contributor. While stubble burning accounted for less than 1% of the day's pollution, transport emissions contributed about 15.72%. The DSS forecasts vehicular pollution to rise to 17.36% on Saturday and 18.41% on Sunday. In Noida, the situation was even more alarming. The Sector 1 monitoring station recorded an AQI of 459 at 4pm, while Sector 116 logged 414....