A recent study has revealed that indoor air pollution can surpass outdoor pollution levels, emphasizing the need for regular monitoring of air quality in homes.
Researchers from the University of Birmingham conducted a two-week study using low-cost sensors to measure particulate matter (PM) in three homes. The results, published in Scientific Reports, showed that indoor pollution levels were not only higher but also more variable than outdoor levels. In some cases, PM2.5 levels exceeded the World Health Organization’s recommended limits for several consecutive days, highlighting the importance of monitoring indoor air quality regularly.
The study found that indoor air pollution is influenced by several factors, including the home’s location, ventilation, and residents’ activities. Both internal sources, such as cooking or traffic, and external factors, such as pollution from nearby restaurants or increased outdoor traffic, contribute to fluctuating indoor air quality. Catherine Rathbone, a co-author of the study, noted: “Our research shows that pollution levels in buildings can be significantly higher than outside, even if the outside air looks clean. Monitoring just one location is therefore not enough.”
Using low-cost sensors, the team was able to build more precise models of indoor pollution and identify key factors affecting particulate matter levels. For example, larger particles (PM10) settle more quickly than smaller ones (PM2.5), which affects the effectiveness of ventilation and air purification systems in homes.
Carried out in the Selly Oak area of Birmingham, the study demonstrated how small changes in daily activities or external conditions can lead to significant variations in indoor pollution levels. The research also highlighted the potential of using low-cost monitoring technologies to assess health impacts, providing a foundation for developing effective policies to improve air quality in households.
Given the availability of affordable pollution monitoring tools, the researchers believe this approach could be scaled up across the UK and globally. This would help create more accurate health models and guide strategies to tackle indoor air pollution more effectively.
