Indoor air pollution: the danger we live with, but rarely see.

When we think about pollution, images of smog-filled skies, traffic fumes, and industrial chimneys often come to mind. But what many of us overlook is that the air inside our homes, offices, and schools can sometimes be more polluted than the air outside. Indoor Air Pollution is a silent but serious problem that directly impacts our health and well-being.

 What is Indoor Air Pollution?

Indoor air pollution refers to the contamination of the air inside buildings from harmful particles, gases, and biological agents. Unlike outdoor pollution, which is often visible, indoor pollutants are invisible, odourless, and can accumulate in confined spaces — making them even more dangerous.

Common Sources of Indoor Air Pollution

Indoor air pollution arises from multiple everyday sources that often go unnoticed. One of the most common contributors is

1. household combustion—cooking with coal, wood, or kerosene stoves generates fine particulate matter (PM2.5) and carbon monoxide, and in poorly ventilated homes, this smoke lingers, causing chronic exposure.
2. Building materials and furnishings also play a role, as paints, varnishes, adhesives, and pressed-wood furniture release volatile organic compounds (VOCs), while asbestos in older constructions can lead to severe lung diseases when its fibres are inhaled.
3. household products such as cleaning sprays, room fresheners, and pesticides emit harmful chemicals, and even synthetic carpets and upholstery may release formaldehyde into the air.
4. dust mites, mold, pet dander, and pollen are known to trigger respiratory allergies, while damp environments encourage the growth of mold spores.

5.Tobacco smoke remains one of the most hazardous indoor pollutants, as second-hand smoke contains more than 7,000 chemicals, many of which are toxic and carcinogenic.

Case Study: Indoor Air Quality in Delhi’s Buildings

A striking example of the seriousness of indoor air pollution comes from a survey conducted by the Centre of Excellence for Research on Clean Air (CERCA), IIT Delhi, the Society for Indoor Environment (SIE), and air quality company Kaiterra. Released on 20th February 2021, the study — known as Project MAQUID (Monitoring of Air Quality in Urban Indoors in Delhi) — examined 37 buildings across Delhi, including schools, colleges, hospitals, offices, restaurants, shopping malls, and cinemas.

The results were alarming:

• PM10 and PM2.5 levels indoors were found to be 2–5 times higher than India’s own permissible limits and 10–15 times higher than WHO safe limits.
• Schools and colleges recorded the highest particulate matter concentrations, with indoor/outdoor ratios above one — indicating that pollution was not just coming from outside but also being generated indoors.
• Tobacco smoke was rampant in offices, hospitals, and even colleges despite smoking bans.
• TVOC levels were particularly high in hospitals and restaurants, linked to cleaning agents, disinfectants, and cooking fumes.
• CO2 levels spiked in hospitals, offices, and restaurants due to poor ventilation and overcrowding. Schools performed slightly better due to natural ventilation, though some still exceeded safe limits.

The study also highlighted contributing factors such as airtight buildings with inadequate ventilation, use of VOC-rich paints and cleaning agents, high occupancy, poorly maintained equipment (photocopiers, printers), and lifestyle habits.

This survey underlines that indoor air quality is not just a rural biomass issue, but a serious urban health risk that requires urgent attention in cities like Delhi.

Health Impacts of Indoor Air Pollution

The World Health Organization (WHO) estimates in 2024 that 3.2 million people die every year from illnesses linked to household air pollution. The risks are particularly high for children, elderly, and people with pre-existing conditions.

• Short-term effects: Headaches, dizziness, eye irritation, coughing, and fatigue.
• Long-term effects: Asthma, chronic obstructive pulmonary disease (COPD), cardiovascular diseases, lung cancer, and impaired brain development in children.

The Delhi study findings confirm these risks, showing that high levels of particulate matter, VOCs, and CO2 in everyday spaces like schools, hospitals, and offices could have long-term health impacts on millions of urban residents.

How to Reduce Indoor Air Pollution

• Improve Ventilation – Keep windows open whenever possible and install exhaust fans in kitchens and bathrooms to ensure a steady flow of fresh air.
• Switch to Clean Energy – Replace coal, wood, and kerosene stoves with cleaner alternatives such as LPG, electricity, or biogas to reduce harmful emissions.
• Choose Safe Building Materials – opt for low-VOC paints and eco-friendly furniture, and regularly check older homes for asbestos to prevent long-term health risks.
• Maintain Indoor Hygiene – Clean carpets using HEPA filter vacuum cleaners and reduce dampness in living spaces to prevent the growth of mold and allergens.
• Use Air Purifiers and Indoor Plants – Install HEPA air purifiers to capture particulate matter and introduce plants like aloe vera, spider plant, and peace lily, which can naturally absorb pollutants.
• Avoid Tobacco Smoke Indoors – Enforce strict no-smoking rules at home and in workplaces to eliminate one of the most dangerous sources of indoor pollution.

The Way Forward

Indoor air pollution is not just a household issue — it is a public health challenge. Governments, organizations, and individuals need to work together to raise awareness, promote cleaner cooking fuels, and set stricter standards for indoor air quality.

The Delhi case study shows that even in modern, urban environments, poorly managed indoor spaces can trap and amplify pollutants. This calls for stronger indoor air quality standards, better building designs, and public awareness campaigns.

After all, we spend nearly 90% of our time indoors. The air inside our homes should nurture us, not harm us. By taking conscious steps, we can make our indoor spaces healthier and safer for everyone.

At Virat Global Lab, (a division of Aseries Environtek India Private limited) we believe that clean indoor air is not a luxury — it is a necessity for a healthy life. Indoor air pollution silently affects our homes, workplaces, schools, and hospitals, putting millions at risk of respiratory and cardiovascular diseases every year.

We are committed to raising awareness, conducting advanced indoor air quality testing, and providing reliable data that helps individuals, institutions, and policymakers take informed steps toward safer environments.

Whether it’s your home, office, hospital, or educational institution, regular indoor air testing is the first step in protecting your loved ones, employees, and communities.

As the most trusted air testing lab in India, we proudly provide services across the country

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