Navi Mumbai, Sept. 27 -- A dense blanket of smog has once again engulfed Navi Mumbai, leaving residents across several neighbourhoods gasping for breath and raising alarm over worsening environmental and public health conditions. For the past week, localities such as Vashi, Kopar Khairane, Ghansoli, and Sanpada have reported thick smoke accompanied by a pungent chemical odour. The haze, which lingers well into the afternoon after settling in overnight, has reduced visibility to a few metres and triggered widespread complaints of breathing difficulties, sore throats, and sleepless nights-particularly among children and senior citizens. While the Maharashtra Pollution Control Board (MPCB) attributes the haze to climatic changes and fog-like conditions, residents insist the smog is chemical in nature. They allege factories in the Mahape and Rabale industrial zones deliberately release toxic emissions during night hours or holidays, such as Fridays when the Thane-Belapur industrial belt remains largely closed, making detection difficult. Social activist Saurabh Pandya, who has been raising the issue for years, said, "It is obvious that chemicals are being released in the air and untreated effluents in the nullah. Despite several protests and complaints, little action has been taken." Residents from Vashi's Sectors 26, 28, and 29, as well as Kopri Gaon and Kopar Khairane's Sector 11, reported waking up to choking air, burning eyes, and coughing fits. Many said they were forced to shut their windows, with elderly citizens struggling the most. Data reflects the scale of the crisis. On Friday morning, Navi Mumbai's Air Quality Index (AQI) surged to 141, with yearly averages around 134-classified as "unhealthy for sensitive groups." Current PM2.5 levels are 7.5 times higher than the World Health Organization's safe limits, putting children, senior citizens, and those with respiratory illnesses at serious risk. PM2.5 levels or fine-particle air pollution, consists of airborne particles measuring less than 2.5 micrometers in aerodynamic diameter. MPCB's regional officer for Navi Mumbai, Satish Padwal, maintained that the haze is "fog due to climatic changes" and said industries were not to blame. "If chemicals were being released, those living and working inside the industrial zones would be affected first," he said. He added that MPCB vigilance teams are inspecting sites daily and nullah repairs have been carried out to block untreated industrial discharge....