Kolkata: Kolkata gasped through another night of toxic air as unabated firecracker bursting on Monday pushed the PM2.5 pollution index into the ‘very poor’ category at all seven monitoring stations between 2 am and 4 am on Tuesday. The fresh onslaught, coming barely 24 hours after Kali Puja night witnessed an unprecedented pollution spike, prolonged the city’s exposure to hazardous firecracker emissions before showers brought some respite.Salt Lake recorded the highest PM2.5 sub-index of 392 around midnight, just eight points short of the ‘severe’ threshold. Rabindra Bharati University on BT Road followed with 386 at 1 am, indicating that the pollution surge continued till morning.However, scattered afternoon showers swept across parts of Kolkata and its adjoining areas, while hail was reported from Howrah. The sudden spell of rain, accompanied by overcast skies, came amid unusually warm and humid conditions in Nov, raising questions about the onset of winter in Bengal.The showers were reported from Kasba, Salt Lake, Behala, Gariahat, Esplanade, Shyambazar and areas along EM Bypass. The city had been under a cloud cover since morning before rain began in isolated pockets around noon.The Alipore meteorological office had forecast light to moderate rain in Kolkata and parts of south Bengal on Tuesday, with thunderstorms and gusty winds reaching speeds of 30–40kmph at isolated places. With Nov entering its second week, residents have begun experiencing a mild chill during the early morning and late evening in several districts. Kolkata, however, continues to experience relatively warm days.Meteorologists expect temperatures to decline gradually. Rain may bring temporary cooling, but a sustained winter chill will depend on clearer skies, drier conditions and the strengthening of northerly winds. However, before the rain, pollution was particularly alarming as pollution levels remained elevated until early morning. Ballygunge peaked at 327 at 4 am, while Fort William recorded 305, Victoria Memorial 308 and Rabindra Sarobar 303 at the same hour. Jadavpur registered its highest reading of 319 at 2 am.The pollution surge followed an even more severe episode on Sunday, when fireworks sent PM2.5 sub-index readings beyond 400 at several stations. At RBU, the index had touched 450, while Salt Lake recorded 444 and Ballygunge 409 during peak revelry. Although Tuesday’s rain offered relief, the successive nights of pollution underscored the failure to contain firecracker use beyond the permitted hours.
