Diwali Begins Sunday as Smog Returns: What Protects Your Lungs

Diwali celebrations begin Sunday just as hazardous winter air settles over South Asia, especially northern India, and health experts say a few practical steps can lower the risk. ABC News reported that checking air quality readings, wearing a well-fitted mask and running a suitable air purifier can reduce exposure to harmful pollutants.

An estimated 1 billion people worldwide celebrate the holiday, which is observed by Hindus and Jains. Fireworks are a tradition, and they add a sharp burst of pollution to air that is already poor.

Why it matters for people celebrating this week

Pollution in the region comes from traffic, factories, construction dust and the burning of crop residues and waste. Weak winds and stagnant winter air let it build up. Shweta Narayan, a public health expert at the Global Climate and Health Alliance, said poor air is a year-round problem in India and that firecrackers make it worse.

Dr. Arvind Kumar, a chest surgeon at Medanta hospital near Delhi and founder trustee of the Lung Care Foundation, said pollution can cause persistent coughing, inflame the airways and trigger asthma-like attacks. He also cited higher risks of pneumonia, heart attacks and strokes. He linked long-term exposure to impaired lung development in children and to lung cancer.

Kumar added that when many households set off fireworks, the combined emissions can worsen air across whole neighborhoods and cities, exposing people who are not taking part. Fireworks pollution can also linger overnight, depending on the weather.

How to read the air quality index

India's index turns pollution measurements into a health warning. Readings of 201–300 mean “poor,” 301–400 “very poor” and 401–500 “severe.” Severe levels can harm even healthy people.

The report advises checking government or privately run websites before going out. Readers should look for data from a nearby monitoring station and note when it was last updated, because a citywide average can hide a polluted neighborhood.

What it means in practice: masks, purifiers and the home

• Masks: Kumar recommends properly fitted N95 or N99 masks outdoors during heavy pollution. N95 filters are designed to capture at least 95% of airborne particles, and N99 filters at least 99%. They do not filter harmful gases. Loose surgical masks, cloth masks and scarves give unreliable protection against fine particles.
• Fit: The mask should cover the nose, mouth and chin, and the nose clip should be shaped and the seal checked each time. Facial hair can break the seal. Kumar said the goal is for “all the breathing” to go through the mask, not around it.
• Who should be careful: A mask should never be put on a child younger than 2. People with heart or lung disease should seek medical advice about mask use. Disposable masks should be replaced when dirty, damaged or hard to breathe through.
• Exercise: Kumar said people should avoid strenuous outdoor exercise during heavy pollution, including in early mornings, when levels can be high.
• Purifiers: Look for a HEPA filter and check the clean air delivery rate, which measures the volume of filtered air the device supplies. The unit needs enough capacity for the room, should sit where people spend the most time, such as the bedroom, and should run consistently. Activated-carbon filters can remove some gases, but no purifier removes every pollutant. Machines that deliberately produce ozone should be avoided because it irritates the lungs.
• Indoor smoke: Kumar said to avoid incense, mosquito coils and candles, whose particles can linger for hours in poorly ventilated rooms. India's health ministry also recommends cutting smoky cooking, using a kitchen exhaust that vents outdoors, and damp-mopping instead of dry sweeping.

Kumar stressed that cleaner indoor air reduces exposure but cannot eliminate pollution's health risks.

Alternatives to fireworks

Electric lights are one way to celebrate while avoiding the toxic gases and smoke from firecrackers, the report said. Narayan was blunt about the choice, saying that anyone who wants to enjoy the festival should avoid bursting firecrackers.

The wider pollution problem

Delhi is especially affected. Fine particle pollution there averaged about 19 times the World Health Organization's annual guideline last year, and air monitors have hit the maximum reading they can display several times in recent years. City authorities have introduced temporary restrictions on construction, industry and vehicles. Public health experts told ABC News such measures often fail to address root causes. The city of more than 20 million people is also carrying out a long-term plan to promote electric vehicles.

Winter smog also affects parts of Pakistan and China, where warmer air can act as a lid that traps colder air and pollution near the ground. The report noted that personal precautions have limits, since they cannot replace cleaner air for everyone.

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Around Prague, based on reporting by ABC News