A new study by Ahmedabad University has found that the air inside homes and buildings can be more polluted than the air outside often by a significant margin.
The research revealed that levels of particulate matter (PM) indoors were up to 2.5 times higher than those recorded outdoors, even when there were no direct indoor sources of pollution. The findings challenge the widely held belief that staying indoors offers protection from air pollution.
The study, conducted across various urban households, also showed that moderate to very poor air quality days were more frequent inside homes than outside. The researchers linked the rise in indoor PM levels to common household practices such as the use of perfumes, disinfectants, room sprays, and even routine activities like cooking.
“People often assume they’re safer indoors, but our data shows that indoor environments may in fact expose people to higher and more prolonged levels of harmful particles,” the researchers noted.
The study highlighted that outdoor air pollution still plays a significant role in affecting indoor air, especially in homes with poor ventilation. Pollutants like PM2.5 from vehicle emissions, dust, and industrial sources can easily enter indoor spaces and accumulate over time.
These findings carry serious public health implications, especially for vulnerable groups like children, the elderly, and people with respiratory conditions, who spend the majority of their time indoors.
Experts say the results underscore the urgent need for greater awareness and better regulation of indoor air quality an area that often receives less policy attention than outdoor pollution.
The Ahmedabad University team has called for more public education, improved air filtration systems in homes and offices, and stricter standards for household products that release pollutants.
As cities across India continue to grapple with worsening air quality, the study sends a clear message: clean air is not guaranteed whether indoors or out.