On the afternoon of 21 October, Delhi's air quality index jumped to 244, tipping into the "poor" band, and GRAP Stage I came into force across Delhi-NCR. If your throat already feels scratchy after the morning walk, you're not imagining it. Understanding AQI health effects helps you decide when to step out, which mask is worth buying and how to keep the air inside your home cleaner.
With Diwali on 8 November and winter on its way, this is the stretch of the year when air in north India often gets worse before it gets better. Here's what each AQI level means for your body, who needs to be most careful, which masks actually work, and the everyday habits that protect your lungs from pollution.
Key takeaways
- Delhi's AQI reached 244 (poor) on 21 October 2026, CAQM put GRAP Stage I into force across Delhi-NCR, and poor air was forecast for the coming days.
- On CPCB's scale, a poor AQI (201 to 300) may cause breathing discomfort with prolonged exposure, and people with heart disease can feel it even with short exposure.
- Children, pregnant women, older adults, outdoor workers and anyone with asthma, lung or heart disease are most at risk.
- A close-fitting N95 or N99 mask helps; cloth, paper and surgical masks, handkerchiefs and scarves don't protect you from fine particles.
- Skip early-morning and late-evening outdoor exercise on poor-air days, and see a doctor for breathlessness, chest pain or wheeze that won't settle.
On this page
- 01Why did GRAP Stage I start in Delhi-NCR?
- 02AQI levels in India: what is a good AQI?
- 03AQI health effects: what polluted air does to your body
- 04Who is most at risk from polluted air?
- 05N95 mask for pollution: which masks actually work?
- 06How to protect your lungs from pollution at home
- 07Is it safe to exercise outdoors when AQI is poor?
- 08Diwali pollution: how to protect yourself from firecracker smoke
- 09Pollution symptoms that need a doctor
Why did GRAP Stage I start in Delhi-NCR?
GRAP Stage I started because Delhi's AQI rose sharply to 244 at 2 pm on 21 October 2026, up from 179 the day before, crossing into the "poor" band. The Commission for Air Quality Management (CAQM) invoked all Stage I actions across the whole NCR with immediate effect, the first time this season.
Forecasts from the India Meteorological Department and IITM expected air to stay poor in the coming days. Stage I targets the biggest local sources of dust and smoke:
- Stricter dust control at construction and demolition sites and on road works.
- Strict enforcement of the ban on open burning of biomass and garbage.
- No coal or firewood in tandoors at hotels, restaurants and open eateries.
- Diesel generators only for emergency or essential use.
What are the four GRAP stages?
GRAP, the Graded Response Action Plan, adds tighter curbs as air worsens. Stage I applies when AQI is poor (201 to 300), Stage II at very poor (301 to 400), Stage III at severe (401 to 450) and Stage IV at severe plus (above 450). The later stages can be switched on in advance when forecasts show air heading there.
AQI levels in India: what is a good AQI?
In India, a good AQI is 0 to 50, and 51 to 100 is satisfactory. The Central Pollution Control Board's National Air Quality Index has six bands, from good to severe, and each is tied to likely health effects. The final AQI is set by whichever of eight measured pollutants, including PM2.5 and PM10, scores worst.
| AQI | Category | PM2.5 (24-hour, µg/m³) | Likely health impact (CPCB) |
|---|---|---|---|
| 0 to 50 | Good | 0 to 30 | Minimal impact |
| 51 to 100 | Satisfactory | 31 to 60 | May cause minor breathing discomfort to sensitive people |
| 101 to 200 | Moderate | 61 to 90 | May cause breathing discomfort to people with lung disease such as asthma, and discomfort to people with heart disease, children and older adults |
| 201 to 300 | Poor | 91 to 120 | May cause breathing discomfort to people on prolonged exposure, and discomfort to people with heart disease even with short exposure |
| 301 to 400 | Very Poor | 121 to 250 | May cause respiratory illness on prolonged exposure; the effect may be more pronounced in people with lung and heart disease |
| 401 to 500 | Severe | Above 250 | May cause respiratory effects even in healthy people and serious health impacts in people with lung or heart disease, even during light physical activity |
AQI health effects: what polluted air does to your body
The short-term AQI health effects are irritated eyes, nose, throat and skin, cough, breathing difficulty, wheezing, chest discomfort, chest pain, headache and dizziness, according to India's Health Ministry. Fine particles called PM2.5 are small enough to travel deep into the lungs, which is why they matter so much.
For people already vulnerable, a bad week can mean flare-ups of asthma and bronchitis, chest infections, worsening COPD (chronic obstructive pulmonary disease), and even heart attacks and strokes, which the Health Ministry lists among the serious effects.
Over years, even lower levels add up. WHO links long-term outdoor air pollution to heart disease, stroke, lung disease and lung cancer, and calls it one of the greatest environmental risks to child health.
Who is most at risk from polluted air?
Those most at risk from pollution are children, especially under 5, older adults, pregnant women, people with lung, heart or stroke-related conditions, and people who work outdoors, such as traffic police, construction workers, road sweepers, roadside vendors and auto drivers. Families who cook on wood or coal indoors face a double dose.
Pollution and children
Children breathe faster than adults and spend more time outside, so they take in more polluted air for their size. India's Health Ministry advises schools to limit outdoor activity and keep break time indoors on poor-air days. If your child's school still holds games outdoors when AQI is above 200, it's fair to ask why.
Masks are tricky for small children: EPA notes certified respirators don't come in sizes made for young children and are only for those aged 2 and over. For little ones, cutting exposure matters more than a mask.
Pollution and pregnancy
India's Health Ministry warns that exposure to air pollution during pregnancy may have consequences for the baby in the womb, and lists pregnant women among the high-risk groups who should restrict outdoor movement on poor-air days. If you're pregnant, ask your doctor before using an N95, as EPA also advises, because a tight respirator makes breathing harder.
N95 mask for pollution: which masks actually work?
A well-fitted N95 or N99 mask (FFP2 is a similar European grade) is the kind that helps against PM2.5. India's Health Ministry says paper masks, handkerchiefs, scarves and cloth are not effective, and EPA says surgical masks won't protect your lungs because they aren't designed to seal to the face.
Choose the right type
Look for N95 or N99 printed on the mask. Fit matters as much as the label: EPA notes that masks with a single strap, or straps that loop around the ears, aren't designed to seal tightly.
Shape the nose clip
It should cover nose to chin. Press the metal strip with both hands so it moulds to your nose, where most leaks happen.
Check the seal
Cup your hands over the mask and breathe out sharply. If you feel air escaping at the edges, adjust and try again. A beard or stubble prevents a good seal.
Replace it as instructed
Disposable N95s aren't meant to be washed. Change one when it gets damp, dirty, damaged or hard to breathe through, and follow the maker's instructions.
A mask is a backup, not a shield. The Health Ministry notes masks help mainly when exposure is short: the walk to the metro, not a long run. If a mask makes you dizzy or breathless, take it off and get indoors.
How to protect your lungs from pollution at home
To protect your lungs from pollution at home, keep doors and windows shut in the early morning and late evening, air rooms between 12 pm and 4 pm if needed, wet-mop instead of sweeping, and cut indoor smoke from agarbattis, mosquito coils, tobacco and angithis. These steps come straight from India's Health Ministry advisory.
Your poor-air home checklist
- Wet-mop floors and wipe surfaces with a damp cloth instead of sweeping. If you vacuum, use one with a HEPA filter.
- Don't burn agarbattis, dhoop or mosquito coils in closed rooms, and skip room-freshener sprays.
- Never use a coal or wood angithi in a closed room, because the build-up of carbon monoxide can be fatal.
- No cigarettes or bidis indoors, and keep the kitchen cross-ventilated while cooking.
- Run the AC on recirculate mode, at home and in the car, and keep car windows up in heavy traffic.
- When you get home, wash your hands and face (here's the right way), rinse your eyes with clean running water and gargle with warm water.
Is an air purifier worth it?
On poor to severe days, the Health Ministry says an air purifier may help indoors. Choose one suited to your room size, keep the room closed while it runs, and clean or replace filters on schedule. Avoid ozone-generating purifiers, which the ministry warns add to indoor pollution.
Is it safe to exercise outdoors when AQI is poor?
When AQI is above 200, it's safer not to exercise outdoors. India's Health Ministry advises avoiding morning and late-evening walks, jogging, running and other strenuous outdoor activity on poor to severe days. During exercise you breathe faster and deeper, pulling more polluted air into your lungs, so move your workout indoors.
- Check the AQI and the forecast before you plan the day.
- Swap the park walk for yoga, skipping, stair climbing or a home workout with the windows closed.
- If you must go out, choose the middle of the day, avoid busy roads and slow-moving traffic, and keep it gentle.
- If you start coughing, wheezing or feel chest tightness, slow down or stop, and see a doctor promptly.
Diwali pollution: how to protect yourself from firecracker smoke
To protect yourself from Diwali pollution, avoid burning firecrackers, stay indoors with windows shut on Diwali nights, and wear an N95 or N99 mask if you must step out. India's Health Ministry warns that firecracker smoke can seriously affect people with heart or lung disease, and asks people with asthma to avoid crackers altogether.
- Restock any prescribed medicines now, before the festive rush and holiday closures.
- Celebrate with diyas, rangoli, lights and sweets. If crackers are burnt nearby, keep children, older relatives and anyone with asthma well away and indoors.
- Shut windows before the evening's crackers begin, and run a purifier in the room where the most vulnerable person sleeps.
- If you're travelling home for the festival, check the AQI at your destination and pack masks. Our festive travel hygiene guide covers the rest of the trip.
If anyone develops breathing difficulty during Diwali, the ministry's advice is to see a doctor immediately. Don't wait until morning.
Pollution symptoms that need a doctor
See a doctor if polluted air leaves you breathless, gives you chest pain or tightness, a cough or wheeze that won't settle, dizziness, or red, watery eyes that don't clear. If you have asthma or COPD and your usual medicines aren't working as well as normal, get medical advice promptly rather than waiting for the air to improve.
Not every October cough is pollution. A cough with a high fever is more likely an infection, so get it checked, and in the post-monsoon months a fever with body ache could also be dengue.
Frequently asked questions
What AQI level is dangerous?
On CPCB's scale, AQI above 200 is poor, and health effects grow from there. At poor (201 to 300), prolonged exposure may cause breathing discomfort, and people with heart disease can be affected quickly. Very poor (301 to 400) may cause respiratory illness, and severe (401 to 500) can affect even healthy people during light activity. Vulnerable groups should take precautions from the moderate band.
What is a good AQI to go outside?
An AQI of 0 to 50 is good and 51 to 100 is satisfactory, and most people can be active outdoors at these levels. From 101 to 200, people with asthma, lung or heart disease, children and older adults may feel discomfort. Above 200, India's Health Ministry advises avoiding outdoor exercise and early-morning or late-evening walks.
Does an N95 mask protect against pollution?
A well-fitted N95 or N99 reduces the fine particles you breathe in, and India's Health Ministry suggests one on poor-air days above AQI 200. It has to seal around your nose and chin. Cloth masks, scarves, handkerchiefs and surgical masks don't seal and give little protection against PM2.5. Pregnant women and people with heart or lung conditions should ask a doctor first.
What is GRAP Stage 1?
GRAP Stage I is the first level of Delhi-NCR's Graded Response Action Plan, applied when AQI is poor (201 to 300). It brings dust control at construction sites, strict enforcement of the ban on open burning, no coal or firewood in restaurant tandoors and limits on diesel generators. CAQM invoked it across the NCR on 21 October 2026 after Delhi's AQI reached 244.
How does pollution affect pregnancy?
India's Health Ministry lists pregnant women among the groups most at risk from air pollution and warns that exposure during pregnancy may have consequences for the baby in the womb. On poor-air days, limit time outdoors, keep indoor air as clean as you can, and talk to your doctor before using an N95, since tight-fitting masks can make breathing harder.
Sources
- 1.Central Pollution Control Board: National Air Quality Index report
- 2.Ministry of Health and Family Welfare (NCDC): Advisory on Air Pollution and Health, November 2025
- 3.World Health Organization: Ambient (outdoor) air pollution fact sheet
- 4.All India Radio News: CAQM invokes Stage I GRAP across NCR as Delhi AQI enters poor category (21 October 2026)
- 5.ThePrint: GRAP-1 curbs imposed in Delhi-NCR as air quality slips into poor category
- 6.US EPA: Protect yourself from wildfire smoke and ash (respirator fit)
- 7.US EPA: Protect yourself from ash (surgical and dust masks)
Team Potent Hygiene
Written by the Potent Hygiene team in Jaipur, the people behind Ovy period care and Looway travel hygiene. Every article is checked against the public health sources listed with it.