Indoor Air Quality  |  August 17, 2026  |  2 min read

Study Finds Indoor Air Pollution Twice as High in Bradford's Most Deprived Households

A 4.5-year research project studying UK homes found that everyday cooking, not outdoor pollution, is the biggest driver of indoor air pollution — and that the most deprived households are bearing the largest burden.

What was the study?

The INGENIOUS project, led by the University of York alongside the Universities of Manchester, Cambridge, and Sheffield, spent 4.5 years studying the sources and behavior of indoor air pollutants in UK homes. Researchers sampled occupied homes in Bradford, England, monitoring the kitchen, lounge, and a bedroom in each home for about two weeks, tracking fine particulate matter (PM2.5), carbon dioxide, temperature, and humidity.

What did they find?

Peak daily PM2.5 concentrations in the sampled homes regularly exceeded World Health Organization guidelines by more than a factor of 10, driven primarily by cooking activity. The most deprived families in the study experienced indoor PM2.5 concentrations twice as high as the least deprived families. Researchers also found that peak indoor pollution levels were driven by indoor activities like cooking rather than outdoor air quality — outdoor pollution only became a meaningful factor indoors when no cooking or cleaning was happening.

What else stood out?

Cooking and air freshener or diffuser use generated very high indoor concentrations of volatile organic compounds (VOCs) in chamber experiments — in some cases hundreds of parts per billion, far exceeding typical outdoor levels. Bedrooms often showed elevated carbon dioxide overnight due to closed doors and windows limiting ventilation. Researchers also found wide variability in pollution levels between households, pointing to household behavior as a major factor alongside housing conditions.

What's the bigger takeaway?

The findings tie into broader housing challenges the researchers observed, including winter underheating and fuel poverty — 7% of sampled households reported they were rarely or never able to keep their home warm in winter. The team says the results reinforce the need to address ventilation and indoor air quality as part of wider housing policy, particularly given the UK's aging building stock and rising fuel costs.

Sources: Air Quality News, INGENIOUS project (University of York), BMC Public Health.