The Barcelona arm of the K-HEALTHinAIR project is structured around four real-life monitoring scenarios: hospitals, metro stations, municipal markets, and patient homes. These environments are being studied with two overarching goals. The first is to characterise indoor air quality (IAQ) in representative public settings. The second is to explore how IAQ may influence respiratory health in vulnerable patient populations.
In alignment with the second aim, a prospective cohort of patients with asthma and/or chronic obstructive pulmonary disease (COPD) is being followed as part of a novel community-based service for the prevention of unplanned hospital admissions. The intervention includes four components: IAQ monitoring using low-cost sensors, home-based oscillometer to detect and track exacerbations, digital tools to support patient engagement and education, and predictive modelling to support early intervention.
Initial insights now emerging focus specifically on the feasibility and clinical relevance of the household air quality monitoring component. Homes in the study cohort have been equipped with compact sensors capable of continuously measuring fine particulate matter (PM2.5), formaldehyde, carbon dioxide (CO₂), temperature, relative humidity, and total volatile organic compounds (tVOCs).
Preliminary data confirm that continuous IAQ monitoring can be integrated into the care routine of patients with complex chronic respiratory conditions. Technical evaluation of the low-cost sensors showed that their performance was appropriate for detecting variations in exposure patterns over time, including assessments of accuracy and measurement drift.
Initial results suggest that exposure to pollutants such as PM2.5 and formaldehyde is common in this population. Although CO₂ levels were generally consistent with adequate ventilation, other parameters revealed variability between households, including evidence of elevated and sustained formaldehyde exposure in a subset of cases. Daily fluctuations in PM2.5 were also observed, particularly in homes where smoking was present.
While clinical follow-up is ongoing, early patterns suggest that patients living in more polluted indoor environments may be more likely to experience acute respiratory events. Although current sample sizes are limited, these trends highlight the potential value of IAQ data in identifying patients at greater risk.
These early findings support the hypothesis that indoor air quality may be an actionable determinant of health in patients with chronic respiratory disease. Monitoring household environmental conditions may help clinicians better understand individual risk profiles, especially when combined with digital health tools and predictive modelling.
According to Dr. Rubèn González-Colom, postdoctoral researcher and lead analyst of the Barcelona study, “This study helps bring environmental data into the clinical conversation. It demonstrates that tracking household air quality is technically feasible, and potentially valuable, as a step toward addressing the environmental determinants of respiratory health.”
The use of low-cost sensors to monitor air quality in the homes of high-risk patients appears both practical and relevant for future clinical applications. These tools offer an accessible method for identifying environmental risk exposures and could complement broader strategies for disease prevention and management.
As the cohort follow-up continues, more robust evidence will be gathered to clarify how IAQ data may inform decision-making in chronic care. The Barcelona pilot contributes to a growing body of knowledge exploring the role of environmental monitoring in person-centred, digitally supported models of care for asthma and COPD.
Funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or of the European Health and Digital Executive Agency (HADEA). Neither the European Union nor the granting authority can be held responsible for them.
