Delhi-NCR under GRAP-3: Hybrid classes allowed as AQI remains 'very poor'

Stage III is the third level of Delhi-NCR's four-stage emergency pollution plan. It is used when air quality reaches the severe range, although authorities invoked it here amid forecasts of further deterioration. Earlier measures remain active, with extra controls on vehicles, construction, mining and industrial pollution.

Primary schools may combine classroom and online lessons. This limits the time young children spend outdoors during dangerous pollution while preserving access to education. The article describes hybrid classes as an option under Stage III, not a complete school closure.

Delhi's average AQI was 364, technically very poor, but several stations were already severe. The Commission for Air Quality Management imposed Stage III two days before Diwali. The aim is to stop pollution worsening into Stage IV, or severe plus, when the AQI crosses 450.

An AQI of 364 falls in the very poor category under GRAP, which covers readings from 301 to 400. It signals seriously degraded air and explains why emergency controls are active. It is not yet in the severe band, which begins at 401 and runs to 500.

The local contrast was striking. IIT Delhi recorded 443, placing it in the severe category. Punjabi Bagh reached 433, and Narela recorded 409. By comparison, Cantonment Area measured 315, Dhaula Kuan 318, and Anand Vihar 272, which was poor.

These figures show that the citywide average can hide dangerous hotspots. The 364 average was a marginal improvement from Friday's 389, but several stations remained severe. Authorities therefore used forecasts and station-level conditions to justify Stage III action.

Stage III targets major pollution sources that can add exhaust and particles to already unhealthy air. Its restrictions cover transport, construction, mining and stone crushing. Measures from earlier GRAP stages continue at the same time.

BS-III petrol and BS-IV diesel four-wheelers are banned in Delhi and designated NCR districts. Older light and medium goods vehicles face tighter curbs, as do non-Delhi-registered diesel commercial vehicles entering the capital. Non-essential high-dust work, including excavation, earthwork, demolition and road construction, is suspended.

Essential projects may continue only with strict dust controls. Stone crushers and mining activities face shutdowns or operating restrictions. Authorities are also told to increase Metro frequency and add buses. These steps seek to reduce vehicle exhaust, construction dust and particulate pollution before conditions enter severe plus.

When air reaches the very poor or severe categories, people face greater health risks from polluted air. The article specifically identifies respiratory and cardiovascular illnesses as concerns. These categories describe pollution severity, not a guarantee that every person will become ill.

The main pollutants named are PM2.5, PM10 and nitrogen oxides. Fine and larger particles can enter the respiratory system, while nitrogen oxides irritate airways and contribute to polluted atmospheric conditions. Exposure risk can be higher when people spend more time outdoors, which helps explain the option of hybrid classes for primary pupils.

Delhi's average AQI was 364, while IIT Delhi reached 443. The emergency curbs aim to reduce emissions before air quality worsens further. Cleaner transport, waste management, and sustained control of construction and industrial emissions remain important for reducing recurring health risks.

Monitoring stations measure air in particular locations, while the citywide AQI is an average. Pollution is therefore not evenly distributed across Delhi. A station near heavier traffic, construction dust or industrial activity may record more pollution than one in a less affected setting.

The article names several sources targeted by GRAP: vehicular emissions, construction dust, mining, stone crushing and industrial pollution. These sources can vary from one neighbourhood to another. IIT Delhi recorded 443, in the severe category, while Anand Vihar recorded 272, in the poor category. That is a 171-point gap.

The article does not state why these two stations differed specifically. Still, the readings show why averages cannot describe every locality. Authorities continue monitoring multiple stations and impose region-wide measures because pollution can shift, worsen and affect adjoining NCR districts.

Diwali can bring extra pollution because firecrackers release smoke and particles. That established factor helps explain why authorities acted two days before the festival. The article itself does not specifically mention firecrackers; it reports forecasts of further deterioration and the timing of the Stage III decision.

Weather affects how pollution disperses. Mist and weak air movement can leave pollutants concentrated near the ground rather than carrying them away. The article reports mist at Safdarjung and a temperature of 17 degrees Celsius at 5.30 am, but it does not report wind strength or directly attribute the readings to weather.

Delhi's average AQI was already 364, and several stations were severe. Authorities therefore sought to prevent entry into severe plus, above 450. Pollution levels may worsen when extra emissions meet stagnant conditions, making transport, dust and industrial controls especially important around Diwali.

PM2.5 means particles no larger than 2.5 micrometres, while PM10 means particles no larger than 10 micrometres. Nitrogen oxides are gases produced mainly when fuels burn at high temperatures. These pollutants matter because they can enter or irritate the respiratory system and contribute to cardiovascular and respiratory illness risks.

Vehicles, industrial activity, construction and machinery can emit these pollutants. Construction and road work also raise dust, while mining and stone crushing generate particulate matter. In Delhi, GRAP targets these sources through vehicle restrictions, dust controls, construction suspensions and limits on mining and crushers.

The article names PM2.5, PM10 and nitrogen oxides as major targets, but it does not provide a pollutant-by-pollutant source breakdown. Its wider point is clear: when emissions accumulate, AQI rises. Cleaner transport, waste management and sustained emission controls are needed to reduce recurring pollution.