Oncologists across Delhi reported a marked rise in pollution-linked cancer cases on Tuesday as the capital's air quality index pushed into hazardous territory with the onset of winter smog. Doctors at the All India Institute of Medical Sciences flagged patients as young as 15 presenting with gastrointestinal tumours.

Physicians at several Delhi hospitals have observed gastrointestinal and lung cancers in unusually young patients, clinicians linked the trend to prolonged exposure to particulate matter. The city's recurring October-to-January pollution crisis stems from stubble burning, vehicle emissions and low wind speeds.

The Central Pollution Control Board recorded PM2.5 concentrations well above World Health Organization safe limits across multiple monitoring stations in the National Capital Region. Doctors at Sir Ganga Ram Hospital and Max Healthcare urged vulnerable residents, including children and the elderly, to limit outdoor activity and use air purifiers indoors.

The renewed alarm placed pressure on the Commission for Air Quality Management to enforce stricter measures under the Graded Response Action Plan. Public health specialists warned that chronic exposure carried long-term carcinogenic risks that extend well beyond respiratory illness.

"We are seeing tumours in patients who have no family history and no other risk factors," said an AIIMS oncologist. "Air pollution is no longer just a lung problem; it is a systemic cancer driver."