Air Quality in India: Understanding AQI, PM2.5, Health Effects, Indoor Air, Masks, Air Purifiers and Daily Protection Tips

Air quality is a daily health issue in much of India, particularly in northern plains during winter, and in many cities with traffic, construction dust and burning of waste or crop residue. You cannot control everything, but you can understand the numbers and reduce your exposure. This guide explains the basics in plain language.

Prices, specifications and product availability change often. Treat figures here as starting points and check current details before buying.

This is general health information, not medical advice. People with asthma, heart or lung disease, pregnancy, young children and older adults should follow their doctor guidance.

What is AQI?

The Air Quality Index converts pollutant concentrations into a single number. India's national AQI, run by the Central Pollution Control Board (CPCB), uses categories commonly described as: Good (0 to 50), Satisfactory (51 to 100), Moderately polluted (101 to 200), Poor (201 to 300), Very poor (301 to 400) and Severe (401 to 500). The index considers several pollutants, and the reported value is based on the worst pollutant at the time. You can check live readings on the CPCB's Sameer app and website, and on various commercial apps that use their own sensors and scales, so numbers may differ.

PM2.5 and PM10: why they matter

• PM10 are inhalable particles of 10 micrometres or less, such as road dust. They irritate the nose and throat.
• PM2.5 are fine particles of 2.5 micrometres or less, from vehicles, combustion, industry and burning. They go deep into the lungs and can enter the bloodstream.
• Other pollutants include nitrogen dioxide, sulphur dioxide, ozone and carbon monoxide.

The World Health Organization guideline for annual PM2.5 is far lower than most Indian cities experience. National standards are less strict than WHO guidelines.

Seasonal patterns

• Winter (Oct to Feb): cold air and low wind trap pollutants. Burning of crop residue, festival fireworks and heating fires add to the load in northern India.
• Summer: dust storms and ozone.
• Monsoon: rain washes particles from the air, and air is usually cleaner.

Health effects

• Short term: cough, throat irritation, watery eyes, headaches, breathlessness, asthma attacks.
• Long term: reduced lung function, chronic bronchitis, heart disease, stroke and lung cancer risk.
• Children breathe faster and have developing lungs. Older adults and those with chronic conditions are more vulnerable.
• Pregnancy exposure is linked with lower birth weight in several studies.

See a doctor if you have persistent cough, wheezing or chest discomfort. See also heart health and blood pressure management.

What to do on high-pollution days

1. Check the AQI before outdoor activity. Postpone exercise outdoors when AQI is poor or worse; exercise indoors instead.
2. Keep windows closed during peak pollution hours, usually early morning and evening in winter, and ventilate when the outdoor air is cleaner (often afternoons).
3. Wear a well-fitted N95 or equivalent respirator outdoors. Surgical or cloth masks do not filter fine particles well. A mask must seal around the nose and cheeks to work.
4. Avoid burning garbage, leaves or incense heavily indoors. Avoid smoking.
5. Stay hydrated and eat a balanced diet. Antioxidant-rich foods such as fruits and vegetables support health, but they do not replace avoiding exposure. See healthy Indian breakfast.

Indoor air

Indoor air can be as polluted as outdoor air. Sources include cooking smoke, mosquito coils, incense, dust, mould, paints and cleaning chemicals.

• Use a chimney or exhaust fan when cooking, and ventilate.
• Avoid chemical sprays and strong fresheners. Choose low-VOC paints. See home decor tips.
• Clean with a damp cloth and a vacuum with a HEPA filter, not dry sweeping.
• Control damp to avoid mould.
• Plants add comfort, but studies show you would need very large numbers to materially clean indoor air. Do not rely on them. See home garden guide.

Choosing an air purifier

• Filter: a true HEPA filter (H13 or similar) captures fine particles. Activated carbon helps with odours and some gases.
• CADR (clean air delivery rate): higher CADR cleans larger rooms faster. As a rule of thumb, the CADR in m3/h should be around 2 to 3 times the room area in square metres for fast cleaning. Check the manufacturer room-size claim carefully.
• Noise level at low and high settings, particularly for bedrooms.
• Running costs: filter replacement every 6 to 12 months and electricity. Estimate power use with the electricity bill calculator.
• Avoid ozone generators and ionisers that emit ozone, which is harmful.
• Keep doors and windows closed in the room where it runs, and place it away from walls.

Car and travel habits

Use recirculation mode in the car in heavy traffic, and keep the cabin filter clean. Avoid peak-hour travel on foot or by two-wheeler where possible. Public transport, carpooling and electric vehicles reduce emissions. See electric vehicle guide.

Children, elders and workers

• Schedule outdoor play when the AQI is better. Keep a spare child-fit mask.
• Keep inhalers and medicines ready for asthma patients, as advised by the doctor.
• Outdoor workers should use respirators if possible and take rest breaks.

Community action

Stop waste burning, use covered construction, plant trees, support clean cooking fuels and report violations to local authorities. Individual choices add up, and collective action matters. Pair this with water conservation for a more sustainable home. For stress about pollution and health, see stress management.

Frequently asked questions

What AQI is considered unhealthy?

Generally 201 and above is Poor, and sensitive people can be affected even earlier.

Do cloth masks protect against PM2.5?

Not well; a fitted N95 or equivalent is more effective.

Do indoor plants clean the air?

Not enough to make a real difference on their own.

What should I look for in an air purifier?

True HEPA filter, suitable CADR for the room size, noise level and filter cost.

When is air quality worst?

Winter in northern India, due to low winds and burning.

Should children play outside on poor air days?

It is better to limit outdoor exertion and prefer indoor activity.

Last reviewed 8 November 2026. Rates, limits and rules change, so confirm figures with the official source before you act.