Indoor Smog We Don’t Talk About - Dr Nalini Nagalla

When we talk about lung health, most people immediately think of smoking or air pollution from vehicles and factories. Inside many Indian homes, a quiet but harmful form of pollution builds up — smoke from mosquito coils, incense, and cooking in closed spaces. These routine habits slowly contaminate the air and strain the lungs over time.

For years, chronic obstructive pulmonary disease (COPD) was seen as a smoker’s illness. Yet today, doctors are treating a growing number of patients — especially women — who have never smoked a cigarette in their lives. The culprit often lies much closer to home.

The Hidden Smoke Indoors

In many Indian homes, incense sticks and mosquito coils are used every day — for prayers, to repel insects, or simply to freshen the air. But what many don’t realise is that these products release a dense smoke filled with fine particles, carbon monoxide, formaldehyde, and other chemicals that irritate the airways.

A single mosquito coil, when burned through the night, can produce as much particulate matter as dozens of cigarettes. In closed rooms without proper airflow, these particles stay suspended long after the smoke fades. With time, they irritate the airways, restrict breathing, and slowly harm lung tissue.

Incense sticks pose a comparable risk. Their soothing fragrance conceals smoke that, when breathed in regularly, can lead to chronic bronchitis or worsen asthma. For women who spend much of their day indoors or near cooking areas, this exposure accumulates silently over time.

The Kitchen Factor

In many Indian homes, especially in rural and semi-urban areas, cooking is still done using biomass fuels — wood, dung cakes, or coal. Even in city homes, kitchens without proper chimneys or exhaust fans trap cooking fumes. The combination of heat, oil vapour, and fine smoke particles from frying can severely affect indoor air quality.

Cooking over an open flame releases nitrogen dioxide and other gases that irritate the lungs. With constant exposure, lung capacity can decline, raising the risk of COPD even among non-smokers. Women, who often spend more time near the stove, are usually the most affected.

It’s not just the fuel — the type of oil and cooking method matter too. Repeatedly heating oil for frying releases fumes that can damage the small airways in the lungs. In homes where kitchens are compact and windows are kept closed for privacy or weather, these vapours have nowhere to escape.

Why Women Are More at Risk

In India and many other countries, the gender divide in lung health has often been overlooked. Women are more exposed to indoor smoke because of household roles, and their smaller airways make them more vulnerable to irritation. Hormonal factors may also amplify inflammation in the lungs.

A woman might never light a cigarette, but she could still inhale enough smoke from her surroundings — incense, mosquito coils, or cooking — to develop symptoms of breathlessness, chronic cough, or fatigue over time. These are often dismissed as minor or age-related, delaying diagnosis.

The Unseen Burden

For doctors, diagnosing COPD in non-smokers can be tricky because the association with indoor pollution is not always recognised. Patients may appear otherwise healthy, with no smoking history, yet present with lung function similar to someone exposed to tobacco smoke for years.

The damage is slow and cumulative. When the airways stiffen and scarring sets in, the damage is permanent and can only be controlled, not cured. That’s why prevention and early awareness are crucial.

Small Changes, Big Difference

Protecting indoor air begins with simple steps:

• Ventilation: Open windows while cooking and run an exhaust fan if you have one. A short burst of fresh air helps clear lingering smoke.
• Safer alternatives: Use electric repellents or natural oils in place of mosquito coils. Burn incense only briefly and keep windows open for proper ventilation.
• Clean cooking: If cooking with LPG, check for leaks and keep windows open. For wood or biomass, use a smokeless stove or cook where air can move freely.
• Air quality checks: Many cities now provide indoor air monitors at affordable rates. Understanding your home’s air quality is the first step toward making it safer.

Rethinking What “Clean Air” Means

Air pollution isn’t only an outdoor problem. The air we breathe inside our homes can be just as harmful — and sometimes worse. The challenge is that we can’t always see or smell the danger. It creeps in quietly, disguised as tradition or routine.

As doctors, we now know that protecting lungs means looking beyond cigarettes and factories. It means talking about kitchens, incense, and mosquito coils with the same seriousness.

The solution begins with awareness. When families understand that the smoke rising from a prayer lamp or a kitchen stove can affect their lungs over time, they can take small steps to change habits. Clean air at home should not be a privilege — it should be a basic part of good health.

Disclaimer: The views expressed in this article are of the author and not of Health Dialogues. The Editorial/Content team of Health Dialogues has not contributed to the writing/editing/packaging of this article.