10th November, 2025: The Birla Institute of Technology & Science (BITS) Pilani, an Institute of Eminence, has taken a significant step toward addressing India’s often-overlooked indoor air pollution crisis. In a collaborative effort with NIT Warangal and IIT Jodhpur, researchers from BITS Pilani’s Hyderabad campus have developed the country’s first India-specific Indoor Air Quality (IAQ) Index. Published in the prestigious Royal Society of Chemistry journal, the study reveals that indoor air in Indian households can be considerably more polluted than outdoor air, primarily due to everyday activities such as cooking, cleaning, and improper waste management.
The study highlights how pollutants such as PM2.5 and PM10 spike during routine household activities, and how poor ventilation allows these particles to accumulate. Seasonal factors like winter smog and Diwali fireworks further exacerbate the problem. The research team argues that India cannot rely on international IAQ standards, as they fail to account for the country’s diverse climate, building styles, and cultural practices.
“People often assume their homes are safe, but our research shows that indoor air can be two to five times more polluted than what we breathe outside,” said Dr. Atun Roy Choudhury, lead researcher on the project. “This is especially concerning because we spend nearly 90% of our time indoors.”
“Our homes are built differently, we cook differently, and our festivals and climate patterns are unique which is why we need an indoor air quality scale that reflects Indian realities, not borrowed benchmarks.” said Prof. Sankar Ganesh, faculty mentor on this project.
The newly proposed IAQ Index is based on real-life data collected from households affected by nearby construction and renovation. Using the Analytical Hierarchy Process (AHP), the team assigned severity weights to various pollutants, creating a relatable and easy-to-understand scale for Indian households, like the outdoor AQI.
The study also draws attention to the impact of stubble burning and dump site emissions on indoor air. Methane, a potent greenhouse gas released from unsegregated waste and large dump yards, poses serious health and climate risks. The researchers urge policymakers to introduce India-specific indoor air guidelines, enforce ventilation standards in buildings, and launch public awareness campaigns on clean cooking and waste management.
According to data and advisories released by the Central Pollution Control Board (CPCB) and SAFAR for 2025, major Indian cities, particularly the Delhi-NCR region, have frequently recorded AQI levels in the ‘Very Poor’ (301-400) and ‘Severe’ (401-500+) categories, with peak readings often surpassing 450 in specific areas. The government has consistently warned that such elevated AQI levels, driven by pollutants like PM2.5 and PM10, pose severe health risks, ranging from breathing discomfort and respiratory illness for most people to serious impacts on healthy individuals and those with pre-existing conditions, necessitating emergency measures and advising against outdoor activities.