Common bacteria found in classroom dust have been associated with reduced lung function in children, according to research presented at the European Respiratory Society (ERS) Congress in Barcelona. The analysis used classroom samples drawn from a large European survey to explore whether bacteria commonly present in dust may affect developing lungs.
Study design and key findings
Researchers analysed dust from nearly 300 classrooms across 22 European countries using samples and health data collected as part of the SINPHONIE study. The team focused on two groups of bacteria — Streptomyces and Mycobacterium spp. — organisms commonly found in soil, dust and water systems.
Children’s lung function was assessed with spirometry, a standard breathing test that measures lung volumes and the speed of exhalation. The investigators adjusted their analyses for a range of potential confounders, including age, sex, body mass index, exposure to passive smoking, pet allergens, socio-economic indicators, the age of school buildings and regional air pollution levels.
The study reported an association between higher classroom levels of Streptomyces and lower spirometry values among pupils. The research team said the findings may help guide efforts to ensure schools are healthier environments for children and for their developing lungs.
"We know that indoor air quality in schools can be affected by pollutants, humidity, ventilation, temperature, dampness and biological agents like fungi and bacteria. However, much less is known about whether the types of bacteria growing in classroom dust are linked to children's lung function," said Dr Soutrik Banerjee, who presented the research.
What this means for schools and parents
The findings highlight classroom dust as a potential contributor to respiratory health differences among children. While the study shows an association rather than proof of cause, it underlines the importance of monitoring and improving indoor air quality in educational settings.
- Key environmental factors in classrooms include ventilation, humidity control and the presence of damp or mould.
- Biological agents in dust — such as bacteria and fungi — may vary by region, building age and maintenance routines.
- Regular cleaning, effective ventilation and prompt remediation of damp problems are established steps that help reduce airborne and dust-borne contaminants.
Health officials and school administrators should consider environmental assessments when addressing respiratory symptoms among pupils. Clinicians assessing children with breathlessness, chronic cough or reduced exercise tolerance should ask about school exposures as part of a broader environmental history, while continuing to investigate common causes such as asthma, allergies and exposure to tobacco smoke.
Limitations and next steps
The researchers accounted for many individual and school-level factors, but the observational design cannot definitively establish causation. Further research is needed to understand biological mechanisms, whether specific strains exert harmful effects, and how interventions in school environments might improve lung function trajectories over time.
Policymakers may wish to consider targeted studies and pilot interventions in schools, including enhanced ventilation, humidity control and strategies to reduce dust accumulation. Such measures would align with broader public health goals to reduce childhood respiratory disease burden.
Parents should seek medical assessment for children who experience persistent respiratory symptoms rather than attempting to self-diagnose or self-treat based on environmental reports. A clinician can advise on appropriate investigations, treatment and referral to environmental health services if necessary.
| Feature | Detail |
|---|---|
| Study | SINPHONIE classroom survey |
| Geography | 22 European countries |
| Samples | Almost 300 classrooms |
| Bacterial groups analysed | Streptomyces; Mycobacterium spp. |
| Health measure | Spirometry (lung function) |
As this research evolves, it should prompt national and local education and health authorities to review school environmental standards and support work that protects children’s respiratory health. Families with concerns about a child’s breathing are advised to consult their doctor or local clinic for assessment and guidance.
