Delhi's air has turned poor: what the pollution season means for your lungs, your heart and your hospital

In short: Delhi's AQI entered the poor band on 21 October 2026. Families can protect themselves by checking the AQI, cutting exposure on bad days, wearing a proper N95 outdoors, keeping medicines at hand and knowing the danger signs.

On Wednesday, 21 October 2026, the day after Dussehra, Delhi’s Air Quality Index climbed from 179 to 245, moving into the “poor” band for the first time this season. It read 227 at 7 am and 248 by 8 pm, and seven monitoring stations, Pusa the highest at 329, were already in the “very poor” range. The Commission for Air Quality Management responded the same day by invoking Stage I of the Graded Response Action Plan (GRAP) across Delhi-NCR, the first and mildest tier of restrictions. The India Meteorological Department and the Indian Institute of Tropical Meteorology expect the AQI to stay poor in the coming days.

This happens every year, and that is exactly why it deserves attention now, before the worst weeks rather than during them. Cooler nights and light winds trap smoke near the ground. Festival fires and firecrackers add to it. And the crop-residue burning season has begun: satellite monitoring by the Indian Agricultural Research Institute counted 287 farm fires across north and central India between 15 September and 6 October, with Madhya Pradesh (118) ahead of Punjab (88) so far. On 21 October farm fires contributed an estimated 3.9% of Delhi’s fine particle pollution, with forecasts of nearly 16% later in the week. Diwali and the peak of the harvest are still ahead.

This is not only a Delhi story. Many cities across the Indo-Gangetic plain see the same winter pattern, and the health advice below applies wherever the AQI is poor or worse.

What the AQI number actually tells you

The AQI, published by the Central Pollution Control Board, turns several pollutants into one number and one of six colour bands. The pollutant that matters most for health in an Indian winter is PM2.5: particles small enough to pass deep into the lungs and, from there, into the bloodstream.

The Union Health Ministry’s advisory links each band to likely effects:

• Good (0–50) and satisfactory (51–100): little risk, though sensitive people may notice minor discomfort in the upper band.
• Moderate (101–200): breathing discomfort for people with lung or heart disease, children and older adults.
• Poor (201–300): breathing discomfort in healthy people on prolonged exposure, and in vulnerable people even on short exposure.
• Very poor (301–400): respiratory illness in healthy people on prolonged exposure; more pronounced illness in vulnerable groups.
• Severe (401–500): respiratory illness even in healthy people, and serious illness in the vulnerable after short exposure.

The CPCB’s Sameer mobile app gives hourly AQI for your city. Checking it before planning outdoor time is the single most useful habit of the season.

Why this matters: the Indian evidence

Air pollution is often discussed as a long-term lung problem. The Indian data show it is also a short-term, heart-and-brain problem, and that it fills emergency departments within days.

The overall burden. The India State-Level Disease Burden Initiative, which includes the Indian Council of Medical Research, estimated that air pollution caused 1.67 million deaths in India in 2019, about 17.8% of all deaths that year. Around 0.98 million were linked to outdoor particulate pollution and 0.61 million to household smoke from solid fuels. Between 1990 and 2019 the death rate from household air pollution fell by about 64%, while the death rate from outdoor particulate pollution more than doubled. The leading causes behind these deaths, as the Health Ministry’s advisory notes, are chronic obstructive pulmonary disease (COPD), heart disease, stroke and lower respiratory infections.

Day-to-day risk. A 2024 study in The Lancet Planetary Health looked at ten Indian cities, including Delhi, Mumbai, Kolkata, Chennai, Bengaluru and Varanasi, from 2008 to 2019. Each rise of 10 µg/m³ in the two-day average of PM2.5 was linked to a 1.4% rise in daily deaths. The effect was about twice as strong (2.7%) on days below India’s own 24-hour standard of 60 µg/m³, which suggests there is no truly safe level. The authors estimated that 7.2% of all daily deaths in these cities were attributable to PM2.5 above the WHO 24-hour guideline of 15 µg/m³.

Emergency departments. A study across two Delhi hospitals enrolled 19,120 children with new respiratory symptoms and found 29% more emergency visits on high-pollution days than on low-pollution days. A companion study of 11,424 adults at two respiratory centres found that emergency visits rose in the two to seven days after particulate levels went up, and that air quality was worst from October to December. That delay matters: the patients from a bad-air weekend arrive through the following week.

Globally, the World Health Organization estimates that outdoor air pollution caused 4.2 million premature deaths in 2019, most from heart disease and stroke rather than lung disease.

Who is most at risk

The Health Ministry names five groups:

• children, whose lungs are still growing and who breathe faster
• pregnant women
• older adults
• people with existing illness, especially asthma, COPD, heart disease, previous stroke and diabetes
• people who work outdoors: traffic police, sweepers and municipal workers, construction workers, street vendors, delivery and transport workers

People who cook on wood, coal or dung, or who smoke, carry an extra load on top of the outdoor air.

What families can do

These steps follow the Union Health Ministry’s advisory under the National Programme on Climate Change and Human Health.

Check the AQI and plan around it. On days when the AQI is above 200:

• skip early-morning and late-evening walks, runs and outdoor exercise, when pollution near the ground is usually highest
• keep doors and windows shut in the morning and late evening; if a room needs air, ventilate between noon and 4 pm
• pregnant women, young children and older people should limit time outdoors as far as possible
• drive with windows closed and set the car’s air conditioning to “recirculate”

Use the right mask, or none. A close-fitting N95 or N99 mask reduces exposure on poor-to-severe days when you must be outside. It has to seal over the nose and mouth, and should be replaced as the maker instructs. Paper masks, handkerchiefs, scarves and cloth masks are not effective against fine particles.

Do not add to the air inside your home. Avoid burning mosquito coils and incense in closed rooms, do not smoke indoors, and never burn coal or wood in an angithi in a closed room: carbon monoxide can kill. Wet-mop floors rather than sweeping. Do not burn leaves, waste or firecrackers.

Air purifiers are optional, not essential. If you use one, choose a size suited to the room, keep the filter clean, and avoid devices that work by generating ozone, which makes indoor air worse.

If you live with lung or heart disease:

• keep taking your regular medicines; do not stop a preventer inhaler because you feel well
• carry your reliever inhaler or prescribed medicines whenever you go out on poor-air days
• avoid strenuous activity when the AQI is high
• know your own warning signs, and seek advice early if symptoms worsen

There is no medicine, supplement or home remedy that protects you from pollution. Reducing exposure is what works.

When to see a doctor, and when to go to hospital

See a doctor soon if you or a family member has breathlessness, a cough that will not settle, chest discomfort, giddiness, or red and watery eyes on poor-air days. If cough, wheezing or chest tightness starts during activity, stop and rest first, then consult a doctor.

Go to an emergency department at once for:

• severe breathlessness, or being unable to speak in full sentences
• chest pain, pressure or tightness, especially spreading to the arm, jaw or back
• sudden weakness, numbness or drooping of one side of the face or body, or slurred speech
• bluish lips or fingertips
• confusion, unusual drowsiness or fainting
• in a child: very fast breathing, the chest drawing in with each breath, or difficulty feeding or waking
• an asthma attack that does not ease with the usual reliever

Do not wait for the air to clear before seeking care for these. Heart attacks and strokes rise with pollution, and every minute counts.

What hospitals can do now

The Health Ministry wrote to every State and Union Territory on 1 November 2025 with an updated air pollution advisory, building on the Health Secretary’s letter of November 2024. Its asks of the health system translate into a practical checklist for any hospital in an affected city.

1. Treat the AQI as a clinical input. Monitor daily AQI and the three-day forecasts, and agree in advance which level triggers your surge plan. Because emergency visits climb over the two to seven days after a pollution spike, the forecast is your early warning. Display the day’s AQI and protective advice in OPD and emergency waiting areas, as the advisory suggests.

2. Join the sentinel surveillance network. Under the National Programme on Climate Change and Human Health, states are asked to name about three or four sentinel hospitals per city, each reporting daily counts of air pollution-related illness seen in the emergency department to the district nodal officer. Those reports are how districts know a surge is happening. If your hospital is a sentinel site, make sure someone owns the daily report and that cases are coded consistently: acute respiratory illness, asthma and COPD exacerbations, acute coronary events and strokes.

3. Prepare the emergency department and wards. The advisory lists the essentials: medicines for acute respiratory, cardiac and cerebrovascular illness; oxygen supply, nebulisers and ventilators; beds, stretchers, wheelchairs and ambulances; and clear referral pathways. Practically, that means checking oxygen stock and bronchodilator and steroid supply before the peak, planning extra emergency beds, and protecting staff rosters for the weeks after Diwali.

4. Triage for the vulnerable. Fast-track breathless children, pregnant women and older patients, and screen every chest-pain and stroke presentation promptly. A pollution surge is not a reason to lower the threshold for missing a heart attack.

5. Reach patients before they arrive. Message known asthma, COPD and heart failure patients with the AQI advice and a reminder to keep medicines on hand. Brief OPD doctors in medicine, paediatrics, respiratory medicine, cardiology and neurology, the departments the advisory singles out.

6. Protect your own staff. Guards, ambulance crews, housekeeping and anyone working outdoors on the campus are among the at-risk occupations. Provide properly fitted N95 masks and adjust outdoor duty on severe days.

7. Learn from your own numbers. Compare this season’s daily emergency respiratory and cardiac counts, admissions and oxygen use with the AQI. Two or three seasons of this data will tell you exactly when to staff up.

Much of this depends on information being easy to pull together. A hospital information system helps by keeping bed, lab and notification data in one place, so that a daily sentinel report or a bed-capacity check takes minutes rather than a ring-round.

The bottom line

The air has turned, a little earlier than many expect and with the worst weeks still ahead. For families, the protective steps are simple: check the AQI, cut exposure on bad days, use a proper N95 if you must be out, keep medicines at hand, and know the danger signs. For hospitals, the evidence is clear that the patients come in the days after a spike, so the time to prepare is while the AQI is still in the 200s.

This article is general health information, not medical advice. In an emergency, go to the nearest hospital.

Frequently asked questions

Does a cloth mask or handkerchief protect against air pollution?

No. The Union Health Ministry's advisory says paper masks, handkerchiefs, scarves and cloth are not effective. A close-fitting N95 or N99 mask can help on days when the AQI is above 200, if it fits well and is replaced as instructed.

At what AQI should I change my plans?

Once the AQI is above 200 (poor or worse), the ministry advises avoiding morning and late-evening walks, runs and exercise outdoors, and staying indoors as far as possible if you are pregnant, elderly, a young child or living with heart or lung disease.

When should someone go to hospital?

See a doctor promptly for breathlessness, cough, chest discomfort, giddiness or eye irritation that does not settle. Go to an emergency department at once for severe breathlessness, chest pain or pressure, bluish lips, confusion or drowsiness, or sudden weakness or drooping on one side of the face or body.