Finding F-1247

“The occupancy restrictions also led to reduced CO2 (122–6,914 mg/m3) than previously observed, with the lowest values in HCs with natural airing.”

Peixoto Assessment of indoor air quality in health clubs: insights into (ultra)fine and coarse particles and gaseous pollutants (2023). Frontiers in public health. Page 1. CKB 5760

Structure

Factor: Carbon dioxide (CO₂)
Population: users and staff of health clubs
Setting: health club, PT
Study design: measurement campaign in eight health clubs in Porto, Portugal, under the occupancy and ventilation restrictions of the pandemic period: particulate matter as PM10 and PM2.5, particle number concentration between 20 and 1000 nanometres, total volatile organic compounds, carbon dioxide, ozone, temperature and relative humidity measured during occupied periods in the cardiofitness and bodybuilding areas and in the group class studios (class 4)
Effect: mean 6,914
Caveat: the study prints carbon dioxide in mass units, not in parts per million

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.