Finding F-0441

“Across all classrooms the average maximum school-day CO2 concentration was 1138 ppm (SD: 562 ppm; 99.9th percentile: 5080 ppm).”

Ge Decision tools for schools using continuous indoor air quality monitors: a case study of CO2 in Boston Public Schools (2025). Lancet Reg Health Am. Page 6. CKB 1363

Structure

Factor: Carbon dioxide (CO₂)
Population: school pupils
Setting: classroom, US
Study design: continuous monitoring of classroom CO2 with a network of 3659 commercial indoor air quality monitors across 125 Boston Public Schools buildings over the 2022-2023 school year, 245 million measurements, school-day statistics after offset correction (class 4)
Effect: mean 1138
Averaging time: school hours over the 2022-2023 school year
Caveat: the value is an average of daily maxima, not a time-weighted mean

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.