Hyderabad: When people think of air pollution, they often picture traffic jams, factory chimneys and smog-covered city skylines. But one of the world’s deadliest forms of air pollution is much closer than many realise, inside the home.

Causes of indoor air pollution

For nearly 2.1 billion people worldwide, cooking a daily meal means burning firewood, charcoal, coal, crop waste, animal dung or kerosene in open fires or inefficient stoves.

The smoke produced from these fuels fills homes with tiny, invisible particles and harmful gases that can damage the lungs, heart and other organs over time.

A hidden public health emergency

According to the World Health Organisation (WHO), household air pollution remains one of the leading environmental health risks globally, despite decades of efforts to promote cleaner cooking.

Unlike outdoor pollution, indoor air pollution often goes unnoticed because it is part of everyday life. Yet its health impact is enormous.

2.9 million deaths in 2021 due to household air pollution

WHO estimates that 2.9 million people died in 2021 due to illnesses linked to household air pollution from cooking with polluting fuels and technologies. It also contributed to around 95 million disability-adjusted life years (DALYs), a measure that reflects years lost due to illness, disability and premature death.

The smoke released from traditional cooking methods contains fine particulate matter (PM2.5), carbon monoxide and other toxic pollutants. These microscopic particles are small enough to travel deep into the lungs and even enter the bloodstream.

Over time, exposure significantly increases the risk of stroke, heart disease, chronic obstructive pulmonary disease (COPD), lung cancer and respiratory infections.

Women and children bear the greatest burden

The health risks are not shared equally.

In many households, women spend several hours each day preparing meals, while children often remain close to their mothers during cooking. As a result, they experience the highest exposure to indoor smoke.

Among children under five, household air pollution is linked to nearly half of all pneumonia-related deaths, making it one of the leading threats to child survival in many low- and middle-income countries.

The burden extends beyond health.

Women and children frequently spend hours collecting firewood or other fuels, reducing time available for education, employment and other productive activities. In some communities, travelling long distances to gather fuel can also expose them to injuries and violence.

More than a health issue

Indoor air pollution is not only a public health concern but also an environmental challenge.

Traditional cooking fuels emit black carbon and methane, both of which are powerful short-lived climate pollutants that contribute to global warming. Smoke escaping from homes also worsens outdoor air quality, particularly in densely populated communities where many households rely on similar cooking methods.

This means that cleaner cooking solutions can improve both public health and climate outcomes simultaneously.

Why clean cooking remains out of reach

Despite improvements in access to electricity and cleaner fuels in several countries, progress remains uneven.

WHO estimates that, if current trends continue, around 1.8 billion people will still lack access to clean cooking by 2030. Rural communities and low-income households continue to face the biggest barriers, including the cost of cleaner fuels, limited infrastructure and lack of reliable energy access.

The organisation recommends transitioning to cleaner energy sources such as electricity, liquefied petroleum gas (LPG), biogas, solar energy, natural gas and alcohol-based fuels.

Where biomass continues to be used, WHO advocates cleaner biomass stoves that meet international emission standards. It also stresses the importance of supportive policies, financing mechanisms and better home ventilation to accelerate the transition.

Small changes can save millions of lives

Reducing household air pollution is about far more than replacing a stove.

It means preventing millions of avoidable deaths, reducing healthcare costs, improving women’s health, protecting children and cutting emissions that contribute to climate change.

While outdoor air pollution often dominates public debate, the greatest danger for billions of people could be beginning inside their own homes.