Diwali haze pushes Delhi AQI to 371, 19 monitoring stations record severe air quality

Delhi's AQI of 371 means the city's air was in the 'very poor' category on Sunday evening. AQI is a combined measure of air pollution, with higher numbers indicating dirtier and more harmful air. The category matters because it signals that exposure is no longer merely unpleasant; health risks become more serious.

The article reports that 19 of 59 monitoring stations recorded 'severe' air at 7 pm. Another 33 stations were 'very poor', while seven were 'poor'. An AQI of 460 at Jahangirpuri therefore crossed into the severe range, above the 401 threshold used for that category.

Very poor air can worsen breathing problems and irritate the eyes, nose and throat. Severe air can affect even healthy people, especially during outdoor activity. Delhi's average AQI for the full day was 376, and the warning system expected conditions to worsen from November 9.

Pollution affected nearly every monitored part of Delhi. At 7 pm, 19 of the city's 59 air-quality stations recorded severe air, and 33 recorded very poor air. Only seven stations remained in the poor category. This shows that the haze was not confined to one neighbourhood.

Jahangirpuri was the worst location, with an AQI of 460. That was 84 points higher than Delhi's average AQI of 376 for the day. The citywide average itself rose from 369 on Saturday, so the most polluted station was substantially worse than an already unhealthy overall reading.

The spread and uneven intensity matter for residents across the capital. People in Jahangirpuri faced the sharpest measured pollution, while other areas also experienced unhealthy air. With firecrackers, traffic and weather conditions continuing to combine, the article expected conditions to deteriorate further.

Very poor or severe air can produce immediate effects that people notice outdoors. Fine particles and other pollutants can irritate the eyes, nose and throat. They can also trigger coughing, chest discomfort and breathing difficulty. People with asthma, heart disease or other respiratory problems are especially vulnerable.

The article gives clear signs from Delhi itself. Residents reported a smoky smell, hazy conditions and reduced visibility on social media. Firecracker emissions added fine particulate matter to the existing pollution burden. When pollution is dense, the air looks hazier and distant objects become harder to see, while inhaled particles can enter deep into the lungs.

These effects make outdoor activity riskier, particularly during the festival's peak celebrations. The article does not provide hospital or symptom totals, so the immediate health burden cannot be quantified from its figures. However, the severe readings and continued forecast indicate that exposure risks were likely to remain high.

Delhi entered Diwali with several pollution sources operating together. The article identifies firecracker emissions, vehicular exhaust and stubble burning in neighbouring states. Weather also mattered. Poor ventilation and weak winds prevented pollutants from dispersing, allowing the combined load to build over the city.

Firecrackers made the situation worse by releasing emissions during celebrations. The article says they added to the existing pollution burden and increased fine particulate matter. This extra burst arrived while transport already accounted for the largest estimated share of Delhi's pollution load, making the atmosphere more difficult to clear.

The result was a smoky smell, haze and reduced visibility reported across different parts of the capital. The Air Quality Early Warning System forecast that air could enter the severe category from November 9 and stay there for several days. The article therefore presents Diwali emissions as an added trigger in an already unfavourable setting.

PM2.5 consists of extremely small airborne particles. Delhi's PM2.5 concentration was the dominant pollution concern on Sunday, and the article links firecracker emissions to the rise in fine particulate matter. Other sources, including vehicles and stubble burning, added to the same pollution mix.

Their small size makes PM2.5 dangerous. Unlike larger particles that may be stopped higher in the airways, these particles can reach deep into the lungs. Some can pass into the bloodstream. Exposure can inflame the respiratory system, worsen asthma and increase strain on the heart and lungs, especially among vulnerable people.

Delhi's poor ventilation allowed these particles to remain concentrated rather than disperse. That helped produce haze, smoky smells and reduced visibility. The article does not provide a PM2.5 concentration, but it identifies PM2.5 as the dominant pollutant and warns that firecracker emissions would add to it during the festival.

Pollutants disperse when air moves and mixes. When winds are weak, emissions from traffic, fires and firecrackers remain close to the ground for longer. Poor ventilation means the atmosphere cannot effectively carry pollution away from Delhi, so concentrations rise over time.

The article gives specific warning thresholds. A ventilation index below 6,000 square metres per second, together with average wind speeds below 10 kilometres per hour, is considered unfavourable for pollutant dispersal. Under such conditions, newly emitted particles join pollution already trapped near the city.

This mechanism helps explain why Delhi's air worsened during Diwali despite pollution coming from several different sources. The Early Warning System flagged poor ventilation as a major concern and forecast severe air from November 9 for the following days. Unless winds and ventilation improve, the accumulated pollution can continue affecting visibility and health.

Delhi uses two systems for different but connected tasks. The Air Quality Early Warning System looks ahead and indicates whether conditions may worsen. In this case, it considered poor ventilation, low wind speeds and the wider pollution situation before forecasting severe air from November 9.

The Decision Support System estimates how much different sectors contribute to Delhi's pollution load. Its Sunday estimate placed transport first, at 19 per cent. It estimated stubble burning at 3.5 per cent on Sunday and projected about 2.99 per cent for Monday. These figures identify likely source shares rather than measuring one single emission event.

Together, the systems provide both a forecast and a source picture. The warning system showed that trapped pollution could persist, while the support system indicated transport was the largest estimated contributor. The article also identifies firecrackers and weather as important factors, with stubble burning expected to decline slightly.