equipment review
CO₂ Accumulation in Sleeping Quarters: A Silent Cognitive Hazard in Lunar Habitats
Dr. Marta Kowalska
· European Lunar Health Authority
Lunar Environmental Medicine · Vol. 1, No. 3 · April 5, 2028
Abstract
CO₂ accumulation in closed sleeping quarters creates measurable cognitive impairment at levels that fall below symptom-awareness thresholds. Monitoring of 40 sleeping quarters across three habitats found that 22% regularly exceeded 2000 ppm during sleep. We describe a low-cost ventilation protocol that resolves the issue.
Carbon dioxide accumulation in small, poorly-ventilated sleeping quarters is a known but underappreciated hazard in submarine and spacecraft environments. In lunar habitats, the combination of smaller per-person air volumes and energy-conservation ventilation settings creates conditions for nightly CO₂ buildup.
We monitored CO₂ levels in 40 individual sleeping quarters across three habitats during normal sleep. Twenty-two percent regularly exceeded 2000 ppm — a level associated with measurable cognitive impairment on next-morning testing (Stroop interference task, working memory). Five quarters exceeded 3500 ppm, a level associated with significant physiological response.
Residents were largely unaware: CO₂ exposure at these levels does not produce obvious symptoms until >5000 ppm. The effects are 'invisible' — next-morning cognitive dullness attributed to poor sleep quality, headache attributed to stress.
The fix is inexpensive: increasing sleeping quarter air exchange rate from 0.5 to 1.5 ACH reduced mean CO₂ to below 1000 ppm in all quarters. We recommend this as a mandatory standard in habitat design and remediation.
We monitored CO₂ levels in 40 individual sleeping quarters across three habitats during normal sleep. Twenty-two percent regularly exceeded 2000 ppm — a level associated with measurable cognitive impairment on next-morning testing (Stroop interference task, working memory). Five quarters exceeded 3500 ppm, a level associated with significant physiological response.
Residents were largely unaware: CO₂ exposure at these levels does not produce obvious symptoms until >5000 ppm. The effects are 'invisible' — next-morning cognitive dullness attributed to poor sleep quality, headache attributed to stress.
The fix is inexpensive: increasing sleeping quarter air exchange rate from 0.5 to 1.5 ACH reduced mean CO₂ to below 1000 ppm in all quarters. We recommend this as a mandatory standard in habitat design and remediation.
Keywords
CO2, carbon dioxide, ventilation, cognitive impairment, sleeping quarters, air quality