New Delhi/Noida, Oct. 17 -- An all-too-familiar haze has returned to the National Capital Region (NCR) on Thursday, cloaking Delhi and its suburbs in a blanket of pollution even before Diwali's firecracker emissions compound the crisis. Data from the Central Pollution Control Board's Thursday bulletin delivered a stark reality check: the top eight most polluted cities in India were all in the NCR, painting a grim picture of what lies ahead as temperatures drop and meteorological conditions turn unfavourable in coming weeks. Ghaziabad gained the notorious distinction of being India's most polluted town on Thursday, topped the list with an Air Quality Index (AQI) of 307 - categorised as "very poor." Ballabhgarh, near Faridabad, followed with 296, Noida with 288, and Greater Noida with 272. Gurugram recorded 260, while Delhi stood seventh with an AQI of 245 - its worst reading of the season so far and the third day of "poor" air. On Wednesday, Noida's air was the foulest in the country, touching 318 in the "very poor" range. Data from multiple monitoring stations in Ghaziabad showed the city blanketed by consistent pollution - Loni recorded an AQI of 339, while Indirapuram and Vasundhara were at 305. In Delhi, five of 39 monitoring stations were in the "very poor" bracket - Anand Vihar (360) was the worst, followed by Wazirpur (352). Noida's Sector 125, home to several construction sites and office complexes, touched 344. Experts said the current conditions are being fuelled by meteorological and human factors - calm winds, a gradual drop in night-time temperatures, and traffic congestion that traps pollutants near the surface. "Winds are becoming calm at night, and temperatures are dipping, leading to accumulation of pollutants," said Mahesh Palawat, vice president at Skymet. "These conditions will persist through Diwali," IMD said that haze is expected over the next two days, with smog likely to set in over the region by Sunday. The minimum temperature in Delhi dropped to 18.1degC on Thursday, the lowest this season, and is forecast to fall further to 17degC on Friday. "As the air cools, pollutants get trapped near the surface. If wind speed remains low, dispersion becomes very difficult," said a senior IMD scientist. "Air quality is likely to remain in the 'poor' range till October 19 and slip into 'very poor' by October 20 and 21."...