Do carbon dioxide, volatile organic compounds and atmospheric pressure affect the cognitive performance of occupants in indoor environments? Results of a large-scale experiment with simulated flights

BACKGROUND: ) and volatile organic compounds (VOCs), has been linked to cognitive impairment in previous studies, even below guideline levels. Most previous studies employed small cross-over designs and varied only one indoor air factor. OBJECTIVE: This study aimed to investigate the influence of various combinations of indoor air parameters at typical and elevated levels on cognitive performance. METHODS: (1200, 2750, 4200 ppm), atmospheric pressure (940, 755 hPa), and a VOC mixture of selected compounds at low, medium, and high concentrations. Eight different cognitive domains were assessed with established tests. RESULTS: Participants rated air quality as good to very good at the end of exposure in all groups. Analyses of variance with pairwise comparisons showed effects of exposure in 2 out of 8 cognitive domains (concentration and figural working memory). None of the observed differences were systematically aligned with the air quality conditions. CONCLUSION: ), and atmospheric pressure up to 8000 ft. elevation had any systematic negative effects on the cognitive abilities of healthy adults. The TVOC results should be viewed with caution, as a specific mixture was used, and other mixtures may occur in other indoor environments. Rigorously designed studies with longer exposure times are recommended.