D2.507 - School dust Streptomyces and Mycobacterium exposure and respiratory health in European children: the SINPHONIE study

School indoor microbiota may influence respiratory and allergic health, but evidence for specific taxa is limited.

In SINPHONIE (22 European countries), Streptomyces spp. and Mycobacterium spp. in classroom dust were quantified and categorised as highest tertile vs lower tertiles. Outcomes included doctor-diagnosed asthma, wheeze and nasal allergy (past 12 months), eczema, irritative cough, and spirometry (FEV₁, FVC, PEF₁). Associations were estimated using generalised estimating equations with school clustering. Models adjusted for age, sex, BMI, passive smoking, pets, socio-economic indicators, housing age and region, and additionally for PM2.5 and NO2.

Analyses included 4,739 pupils linked to 294 classrooms. Higher Streptomyces exposure was associated with lower odds of doctor-diagnosed nasal allergy (OR = 0.60, 95% CI: 0.43, 0.84) and wheeze (OR = 0.75, 95% CI: 0.58, 0.99). Higher Streptomyces exposure was also associated with lower FVC (β = −0.079 L, 95% CI: −0.157, −0.001). Mycobacterium exposure showed no robust associations with binary outcomes, but was associated with lower FEV₁ (β = −0.062 L, 95% CI: −0.114, −0.009) and lower PEF₁ (β = −0.133 L, 95% CI: −0.254, −0.012).

In European schools, higher Streptomyces exposure was linked to fewer allergy/wheeze symptoms but slightly lower lung volumes, while higher Mycobacterium exposure was linked to modestly poorer expiratory function. Longitudinal studies are needed to clarify mechanisms and contextual determinants.