The effect of air quality on sleep and cognitive performance in school children aged 10-12 years: a double-blinded, placebo-controlled, crossover trial

• Published in: International journal of occupational medicine and environmental health 2023-05, Vol.36 (2), p.177-191
• Main Authors: Klausen, Frida Bejder, Amidi, Ali, Kjærgaard, Søren K, Schlünssen, Vivi, Ravn, Peter, Østergaard, Kirsten, Gutzke, Vibeke Heitmann, Glasius, Marianne, Grønborg, Therese Koops, Hansen, Stefan Nygaard, Zachariae, Robert, Wargocki, Pawel, Sigsgaard, Torben
• Format: Article
• Language: English
• Subjects: Air cleanliness; Air pollution; Air Pollution, Indoor - adverse effects; Air Pollution, Indoor - analysis; Air quality; Carbon dioxide; Carbon Dioxide - analysis; Child; Children & youth; co2 exposure; Cognition; Cognition & reasoning; Cognitive ability; Cross-Over Studies; Double-Blind Method; Efficiency; Elementary school students; Environmental aspects; Health aspects; Humans; indoor air; Indoor air quality; Original Paper; Pediatric research; Pilot projects; Psychological aspects; rct study; school children; Sleep; sleep quality; University students; Ventilation; VOCs; Volatile organic compounds
• ISSN: 1232-1087; 1896-494X
• DOI: 10.13075/ijomeh.1896.02032

To investigate the effect of CO during sleep on next-morning cognitive performance in young schoolchildren, the authors performed a double-blind fully balanced crossover placebo-controlled study. The authors included 36 children aged 10-12 years in the climate chamber. The children slept at 21°C in 6 groups each at 3 different conditions separated by 7 days in a random order. Conditions were as follows: high ventilation with CO at 700 ppm, high ventilation with added pure CO at 2000-3000 ppm, and reduced ventilation with CO at 2-3000 ppm and bioeffluents. Children were subjected to a digital cognitive test battery (CANTAB) in the evening prior to sleep and on the next morning after breakfast. Sleep quality was monitored with wrist actigraphs. There were no significant exposure effects on cognitive performance. Sleep efficiency was significantly lower at high ventilation with CO at 700 ppm which is considered to be a chance effect. No other effects were seen, and no relation between air quality during sleep and next-morning cognitive performance was observed in the children emitting an estimated 10 l /h per child. No effect of CO during sleep was found on next day cognition. The children were awakened in the morning, and spent from 45-70 min in well-ventilated rooms before they were tested. Hence, it cannot be precluded that the children have benefitted from the good indoor air quality conditions before and during the testing period. The slightly better sleep efficiency during high CO concentrations might be a chance finding. Hence, replication is needed in actual bedrooms controlling for other external factors before any generalizations can be made. Int J Occup Med Environ Health. 2023;36(2):177-91.