Finding F-1506

“A twofold increase in shared classroom time was associated with higher transmission (RR 3.17, 95%-CI 1.96–5.17).”

Banholzer The relative contribution of close-proximity contacts, shared classroom exposure and indoor air quality to respiratory virus transmission in schools (2025). Nat Commun. Page 4. CKB 1478

Structure

Factor: Carbon dioxide (CO₂)
Outcome: Respiratory infections
Setting: classroom
Study design: study of respiratory virus transmission in school classes: close-range proximity time, shared classroom time and air quality measured against transmission with pairwise accelerated failure time models (class 3)
Effect: RR 3.17 (1.96–5.17)
Caveat: the exposure is time in the room, and the air quality enters the model as a separate contribution rather than as a concentration

A Finding records what one published document states, verbatim and with its page. It is not a conclusion of Coridum; see the Claims that build on it.