Air pollution in India’s capital, New Delhi, worsened sharply on Sunday, reaching a new severe level and prompting authorities to enforce the strictest anti-pollution measures while urging residents, particularly vulnerable groups, to remain indoors.

According to data from the Central Pollution Control Board (CPCB), Delhi’s air quality index (AQI) surged to 491 out of 500 on Sunday morning, placing it firmly in the “severe” category. The reading marked a significant deterioration from Saturday evening, when the AQI stood at 441.

In response to the escalating pollution, the Commission for Air Quality Management (CAQM) on Saturday activated Stage IV, the highest level of the Graded Response Action Plan (GRAP). The move was confirmed in a statement issued by the Ministry of Environment, Forest and Climate Change.

Under Stage IV restrictions, the entry of older diesel trucks into the capital has been banned, construction activities—including public infrastructure projects—have been halted, and schools have been directed to adopt hybrid or online modes of instruction to reduce exposure.

Authorities have advised residents to limit outdoor activities, with particular caution directed toward children, the elderly, and people suffering from respiratory or cardiovascular conditions. Citizens have also been urged to wear protective masks if going outside is unavoidable.

The CAQM attributed the rapid deterioration in air quality to high humidity levels and a shift in wind direction, which have hindered the dispersion of pollutants and contributed to the accumulation of dense smog over the city.

Delhi frequently experiences hazardous air pollution during the winter months due to a combination of vehicular emissions, industrial pollution, construction dust, and unfavorable weather conditions. Officials said they would continue to monitor the situation closely and take additional measures if air quality fails to improve. (ILKHA)