Are Cognition and Sleep Affected by Exposure to Carbon Dioxide and Bio Effluents During Sleep?
Study Details
Study Description
Brief Summary
The aim of the project is to examine whether children's sleep and cognition are affected by exposure to CO2 and other bio effluents during sleep. The participants of the study are 36 children recruited from local schools in Aarhus, Denmark.
The study takes place in the climate chambers at the Department of Public Health, Aarhus University. These chambers allow for experimental testing on humans with advanced exposure generation while avoiding contamination from other sources and controlling temperature, humidity, noise, odor, and light.
The children will be sleeping in the chambers under three different conditions:
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One night of good ventilation with a CO2 level of maximum 800 ppm
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One night of good ventilation with high levels of CO2 (3,000 ppm)
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One night of poor ventilation with high concentrations of CO2 (3000 ppm) and other bio effluents.
The study is a within-group design, and groups of six children will be sleeping in the chambers for three nights (separated by seven days). The different groups of children are exposed to the conditions in a randomized order. The study is double-blinded (of security reasons the persons responsible for CO2 concentrations in the chambers are not blinded).
The study takes place on schools nights. The children arrive at 6 pm and leave for school the morning after. In the evening the children are tested for approximately 30-40 minutes to measure their cognitive performance using CANTAB (Cambridge Neuropsychological Test Automated Battery) on iPads. After completing the test, dinner is served and the children have some spare time before going to bed. During night, the quality of sleep (awake time and different sleep stages) will be monitored using Fitbit devices. Sleep quality will also be evaluated using a short sleep questionnaire. The next morning the cognitive performance of the children will be tested again using CANTAB before the children leave for school.
Our primary hypothesis is that children will perform worse on the cognitive test when exposed to high levels of CO2 and other bio effluents than compared to low levels of CO2 and bio effluents in a well-ventilated room. In addition to that our secondary hypotheses are:
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Children will perform worse on the cognitive test when exposed to high levels of CO2 and other bio effluents than compared to CO2 alone.
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Children will sleep less well in an environment with poor ventilation and high levels of CO2 and other bio effluents compared to sleeping in a well-ventilated room with low levels of CO2.
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Children will sleep less well in an environment with poor ventilation and high levels of CO2 and other bio effluents compared to sleeping in a room with high levels of CO2 alone.
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Children will sleep less well and perform worse on the cognitive test when exposed to high levels of CO2 compared to low levels of CO2.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
N/A |
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Other: Group 1 One night of good ventilation with a CO2 level of maximum 800 ppm One night of good ventilation with high levels of CO2 (3000 ppm) One night of poor ventilation with high concentrations of CO2 (3000 ppm) and other bio effluents (The order of the three conditions are randomized) |
Other: Good ventilation
Good ventilation with a low concentration of CO2
Other: Ventilation CO2
CO2 High and Good ventilation
Other: Poor Ventilation
Poor ventilation with high concentrations of CO2 and bio effluents
|
| Other: Group 2 One night of good ventilation with a CO2 level of maximum 800 ppm One night of good ventilation with high levels of CO2 (3000 ppm) One night of poor ventilation with high concentrations of CO2 (3000 ppm) and other bio effluents (The order of the three conditions are randomized) |
Other: Good ventilation
Good ventilation with a low concentration of CO2
Other: Ventilation CO2
CO2 High and Good ventilation
Other: Poor Ventilation
Poor ventilation with high concentrations of CO2 and bio effluents
|
| Other: Group 3 One night of good ventilation with High CO2 level of maximum 800 ppm One night of good ventilation with high levels of CO2 (3000 ppm) One night of poor ventilation with high concentrations of CO2 (3000 ppm) and other bio effluents (The order of the three conditions are randomized) |
Other: Good ventilation
Good ventilation with a low concentration of CO2
Other: Ventilation CO2
CO2 High and Good ventilation
Other: Poor Ventilation
Poor ventilation with high concentrations of CO2 and bio effluents
|
| Other: Group 4 One night of good ventilation with a CO2 level of maximum 800 ppm One night of good ventilation with high levels of CO2 (3000 ppm) One night of poor ventilation with high concentrations of CO2 (3000 ppm) and other bio effluents (The order of the three conditions are randomized) |
Other: Good ventilation
Good ventilation with a low concentration of CO2
Other: Ventilation CO2
CO2 High and Good ventilation
Other: Poor Ventilation
Poor ventilation with high concentrations of CO2 and bio effluents
|
| Other: Group 5 One night of good ventilation with a CO2 level of maximum 800 ppm One night of good ventilation with high levels of CO2 (3000 ppm) One night of poor ventilation with high concentrations of CO2 (3000 ppm) and other bio effluents (The order of the three conditions are randomized) |
Other: Good ventilation
Good ventilation with a low concentration of CO2
Other: Ventilation CO2
CO2 High and Good ventilation
Other: Poor Ventilation
Poor ventilation with high concentrations of CO2 and bio effluents
|
| Other: Group 6 One night of good ventilation with a CO2 level of maximum 800 ppm One night of good ventilation with high levels of CO2 (3000 ppm) One night of poor ventilation with high concentrations of CO2 (3000 ppm) and other bio effluents (The order of the three conditions are randomized) |
Other: Good ventilation
Good ventilation with a low concentration of CO2
Other: Ventilation CO2
CO2 High and Good ventilation
Other: Poor Ventilation
Poor ventilation with high concentrations of CO2 and bio effluents
|
Outcome Measures
Primary Outcome Measures
- Reaction time (Simple) [10 hours post start of exposure]
Reaction time in milliseconds. Outcome from CANTAB RTI Simple.
Secondary Outcome Measures
- CANTAB global composite score [10 hours post start of exposure]
CANTAB global composite score = outcomes from CANTAB transformed into a global composite score.
- Reaction Time (Five-Choice) [10 hours post start of exposure]
Reaction time in milliseconds. Outcome from CANTAB RTI Five-Choice.
- Sleep efficiency [Sleep measured for 9 hours during exposure in bed from 9 pm to 6 am.]
Sleep efficiency = Percentage of time in bed spent sleeping.
Eligibility Criteria
Criteria
Inclusion Criteria:
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Healthy children or children with a well-treated chronic disease not interfering with cognition and sleep quality
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Being able to accomplish a CANTAB test
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Completed questionnaires of sleep patterns
Exclusion Criteria:
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Unable to spend three nights (separated by seven days) in the climate chambers
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Conditions that prevent safe access to the chambers such as claustrophobia
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Aarhus University, Department of Public Health, Section for Environment, Occupation and Health | Aarhus | Denmark | DK-8000 |
Sponsors and Collaborators
- University of Aarhus
Investigators
- Principal Investigator: Torben Sigsgaard, Department of Public Health - Institute of Environmental and Occupational Medicine, Aarhus University
Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- 111017