A recent study conducted in residential buildings in Copenhagen and Odense examined the relationship between indoor environmental conditions, specifically temperature and relative humidity, and the onset of eye, nasal, and throat irritation symptoms.

Led by the Department of the Built Environment at Aalborg University, the research combined survey responses from 75 residents with environmental measurements collected between March and May 2023. While the findings suggest that low humidity levels may exacerbate mucosal discomfort, the variability in reported symptoms points to the influence of additional environmental factors. These include indoor air pollutants such as fine particulate matter (PM2.5) and volatile organic compounds (VOCs), as well as the performance of ventilation systems.

The study underscores the importance of maintaining relative humidity between 30% and 50%, in line with EN 16798-1 standards, to support occupant comfort and health. However, the authors emphasise the complexity of factors affecting indoor air quality (IAQ) and its impact on human health, highlighting the need for more comprehensive studies that incorporate ventilation parameters and pollutant levels to better understand the mechanisms behind mucosal irritation in residential settings.