Health Effects of Indoor Air Filtration in Healthy Chinese Adults

Study Overview
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Brief Summary
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This study aims to detect serum metabolite changes, as well as other health indicators with the intervention of air purifiers on a randomized, crossover, double-blind trial.

Detailed Description
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The investigators conducted a randomized double-blind crossover trial among 60 healthy college students in Shanghai, China from November to December, 2015. These students lived in dormitories that were randomized into two groups and alternated the use of true or sham air purifiers for 9 consecutive days with a 2-week wash-out interval. All participants and research staffs were blinded to the group assignment. All participants were required to stay in their dormitory with the windows/doors closed for at least 50% of the time on weekdays and for 80% on weekends throughout the 9-day intervention period. All interventions started at 7 a.m. to avoid issues related to diurnal variation. Health endpoints, including blood pressure, fractional exhaled nitric oxide were evaluated and biological samples such as morning urine, fast blood and buccal cells were collected at baseline and immediately after the completion of each intervention period.

Official Title
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Health Effects of Indoor Air Filtration in Healthy Chinese Adults: An Intervention Study

Conditions
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Blood Pressure

Intervention / Treatment
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* Behavioral: Air Purifiers
* Behavioral: Sham Air Purifiers


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy university students in Jiangwan Campus, Fudan university Non-smoking, no history of alcohol or drug abuse Free of chronic cardiovascular, respiratory, liver and kidney disease Spend at least 50% (weekdays) or 80% (weekends) of time indoors Exclusion Criteria: Current or ever smokers History of asthma, chronic bronchitis，cough, hypertension or other chronic inflammatory disease acute infections medication use in recent one month

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 30 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Air purifiers<br>Participants in this group received an intervention of true air purifiers placed in the center of the room. | Behavioral: Air Purifiers<br>* The 17 dormitory rooms and their residents were randomized into two groups: the intervention and control group. The intervention group went through a 9-day intervention with an air purifier placed in the center of the room. All rooms in this group used the same qualified air purifiers (model KJEA200e, 3M), and all participants were required to stay in their dormitory rooms with the windows/doors closed throughout intervention period. All participants and research staffs were blinded to the group assignment.<br>|
| Sham Comparator: Control<br>Participants in this group received an intervention of sham air purifiers, which were under the same conditions as the true purifiers except the filter gauze in them were removed. | Behavioral: Sham Air Purifiers<br>* The control group went through a 9-day intervention with a sham air purifier (with its filter gauze removed) placed in the center of the room. All rooms used the same air purifiers (model KJEA200e, 3M) as the intervention group, except the filter gauze was removed. During the study period all participants were required to stay in their dormitory rooms with the windows/doors closed. All participants and research staffs were blinded to the group assignment.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes of Serum Cortisol Levels | Using metabolomic methods to screen and quantify all the serum metabolites, and calculate changes in main metabolites in sham purification compared to real purification. Relative intensity was calculated by dividing the peak intensity of cortisol with the peak intensity of internal standard (2-chloro-D-phenylalanine methanol solution, 0.014mg/mL) | at the end of each 9-day intervention period | 
| Changes of Serum Cortisone Concentration | Use metabolomic methods to screen and quantify all the serum metabolites, and calculate changes in main metabolites in sham purification compared to real purification. Relative intensity was calculated by dividing the peak intensity of cortisone with the peak intensity of internal standard (2-chloro-D-phenylalanine methanol solution, 0.014mg/mL) | at the end of each 9-day intervention period | 
| Changes of Serum Epinephrine Concentrations | Use metabolomic methods to screen and quantify all the serum metabolites, and calculate changes in main metabolites in sham purification compared to real purification. Relative intensity was calculated by dividing the peak intensity of epinephrine with the peak intensity of internal standard (2-chloro-D-phenylalanine methanol solution, 0.014mg/mL) | at the end of each 9-day intervention | 
| Changes of Serum Norepinephrine Concentration | Use metabolomic methods to screen and quantify all the serum metabolites, and calculate changes in main metabolites in sham purification compared to real purification. Relative intensity was calculated by dividing the peak intensity of cortisol with the peak intensity of internal standard (2-chloro-D-phenylalanine methanol solution, 0.014mg/mL) | at the end of each 9-day intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Systolic Blood Pressure | To eliminate possible error, blood pressure for each participant were conducted by the same working staff using the same instrument. Average levels were calculated by treatments (intervention or control). | at the end of each 9-day intervention period | 
| Diastolic Blood Pressure | To eliminate possible error, blood pressure for each participant were conducted by the same working staff using the same instrument. Average levels were calculated by treatments (intervention or control). | at the end of each 9-day intervention | 
| Pulse Pressure | To eliminate possible error, blood pressure for each participant were conducted by the same working staff using the same instrument. Average levels were calculated by treatments (intervention or control). | at the end of each 9-day intervention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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PM2.5, metabolomics, air purification, randomized controlled trial, Metabolites, exhaled nitric oxide