Bhubaneswar: Air quality in Bhubaneswar plunged to the severe category on Diwali night, as pollution levels reached alarming heights due to extensive bursting of firecrackers across the city.The state capital recorded an average Air Quality Index (AQI) of 522 on Sunday, significantly worse than last year’s Diwali, when it had remained in the very poor category. Neighbouring Cuttack recorded an AQI of 287, remaining in the poor category but substantially lower than Bhubaneswar.A dense blanket of smoke enveloped several areas of Bhubaneswar and neighbouring Cuttack, reducing visibility to nearly 10 metres in some localities. Residents across the twin cities complained of nasal congestion, sneezing, irritation in the eyes and breathing difficulties as pollution levels surged during and after the celebrations.“When cracker bursting stopped, our neighbouring building was not visible. My daughter returned with a blackened face as cracker dust filled her face, and she was breathless as well. I consulted a doctor and gave her anti-allergic pills,” said Suman Patnaik, a resident of Nayapalli, Bhubaneswar.According to State Pollution Control Board senior environmental scientist Niranjan Mallick, the highest pollution levels were recorded between 7 pm and 11 pm in Bhubaneswar, coinciding with peak cracker-bursting activity. Areas such as Unit-VIII, Palasuni, Khandagiri, Capital police station area, IRC Village and Nayapalli emerged as major pollution hotspots, with particulate matter (PM 2.5) concentrations far exceeding permissible limits.Data collected by the pollution monitoring station showed that PM 2.5 levels reached 589 micrograms per cubic metre (μg/m³) at Unit-VIII, the highest in the city. The permissible limit for PM 2.5 is 60 micrograms per cubic metre. Other severely affected areas included IRC Village, where PM 2.5 levels reached 488 micrograms per cubic metre, and Palasuni, where it was 428 μg/m³.The data indicated that PM 2.5 concentrations were nearly 10 times above the permissible limits at Unit-VIII and over eight times higher at IRC Village during the peak celebration period. In comparison, the Lingaraj Temple area recorded an AQI of 278, while the monitoring station near LV Prasad Eye Institute in Patia reported a relatively lower AQI of 117.“Compared with last year’s AQI, it has exceeded permissible limits far beyond, with high PM 2.5 pollutant, a microparticle that can enter the lungs, this year. It is more because people perhaps continued bursting crackers till late at night in Bhubaneswar, which was not seen in Cuttack,” Mallick said.Medical experts cautioned that elevated particulate pollution poses serious health risks. Medicine specialist Dr K S Kumar explained that while PM 10 particles mainly affect the upper respiratory tract, finer PM 2.5 particles can penetrate deep into the lungs and remain there for prolonged periods, increasing the risk of respiratory ailments and aggravating existing health conditions.