Effect of Short-term Portable Air Purifier Use on Occupant Health Indicators

Study Overview
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Brief Summary
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The purpose of this research project is to examine whether short-term use of portable air pollution filtration can result in changes in indoor airborne pollutants and impact on cardiovascular and respiratory health outcomes of the inhabitants.

Detailed Description
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This study will focus on evaluating the short-term benefits of a common portable air purifier technology in reducing air pollutant exposure and the anticipated concomitant health impacts. High ambient levels of various air pollutants in the Shanghai area serve as a useful model to test the portable air purifier intervention in a realistic setting. As most people using a portable air purifier would only be able to do so in their residences, the investigators have designed our study only to test residential air purifier use. Our hypothesis is that the reduction in pollutant concentrations in indoor air caused by the air purifier will result in measurable reductions in risk factors for cardiovascular and respiratory diseases.

Official Title
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Effect of Short-term Portable Air Purifier Use on Occupant Health Indicators

Conditions
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Non-smoking, Healthy Adults

Intervention / Treatment
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* Device: True-Washout-Sham Air Filtration Intervention
* Device: Sham-Washout-True Air Filtration Intervention


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy, non-smoking adults Live in the dormitory building at Shanghai First People's Hospital (South Section). Exclusion Criteria: Current smokers Has any of the following diseases: chronic respiratory, cardiovascular, liver, renal, hematological disease; diabetes mellitus; Has any other diseases that may confound or complicate the effects of the intervention Pregnant females

Ages Eligible for Study
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Minimum Age: 18 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 |
| --- | --- |
| Active Comparator: Group A: True-Washout-Sham<br>Subjects in group A receives true air filtration intervention, then at least two weeks of washout period, followed by sham air filtration intervention. | Device: True-Washout-Sham Air Filtration Intervention<br>* This intervention involved three sequential steps: (1) 12 to 20 hours of true air filtration intervention; (2) at least two weeks of washout period; (3) 12 to 20 hours of sham air filtration intervention. In the indoor environment, the portable filtration device drew room air, sent it through filter and active carbon (for true filtration) or active carbon alone (sham filtration) and then delivered processed air back to room air. In the study the portable filtration device processes 2.8 cubic meter of room air per minute. The washout period lasted for at least two weeks where no filtration intervention was implemented.<br>|
| Active Comparator: Group B: Sham-Washout-True<br>Subjects in group B receives sham air filtration intervention, then at least two weeks of washout period, followed by true air filtration intervention. | Device: Sham-Washout-True Air Filtration Intervention<br>* This intervention involved three sequential steps: (1) 12 to 20 hours of sham air filtration intervention; (2) at least two weeks of washout period; (3) 12 to 20 hours of true air filtration intervention. In the indoor environment, the portable filtration device drew room air, sent it through filter and active carbon (for true filtration) or active carbon alone (sham filtration) and then delivered processed air back to room air. In the study the portable filtration device processes 2.8 cubic meter of room air per minute. The washout period lasted for at least two weeks where no filtration intervention was implemented.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline FEV1 (forced expiratory volume in the first second of exhalation) within 2h after the filtration intervention | FEV1 (forced expiratory volume in the first second of exhalation, unit: liter) was measured by spirometry in all subjects within 2h after the filtration intervention to compare to FEV1 value of study subjects at baseline (i.e. at start of the study). | Within 2h after the filtration intervention | 
| Change from baseline R5 (airway resistance measured at 5Hz) within 2h after the filtration intervention | R5 (airway resistance measured at 5Hz) was accessed by impulse oscillometry in all subjects within 2h after the filtration intervention to compare to the R5 value of study subjects at baseline (i.e. before the start of intervention). | Within 2h after the filtration intervention | 
| Change in baseline exhaled nitric oxide (eNO) within 2h after the filtration intervention | Exhaled nitric oxide (eNO) was measured in all subjects within 2h after the filtration intervention to compare to the exhaled nitric oxide measurement of study subjects at baseline (i.e. before the start of intervention). Exhaled breath is collected in air sampling bags, and the concentration of NO was quantified by Thermo Scientific model 42i (NO-NO2-NOx) analyzer. | Within 2h after the filtration intervention | 
| Change in exhaled nitric oxide (eNO) at 6h after filtration intervention compared to baseline | Exhaled nitric oxide (eNO) was measured in all subjects 6h after filtration intervention to compare to the exhaled nitric oxide measurement of study subjects at baseline (i.e. before the start of intervention). Exhaled breath is collected in air sampling bags, and the concentration of NO was quantified by Thermo Scientific model 42i (NO-NO2-NOx) analyzer. | 6h after filtration intervention | 
| Change from baseline PWV (pulse wave velocity) within 2h after the filtration intervention | PWV (pulse wave velocity) was measured by the VICORDER instrument in all subjects right after filtration intervention to compare to the PWV value measured at baseline (i.e. before the start of intervention). | Within 2h after the filtration intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline urinary biomarkers of inflammation and oxidative stress at 0h after the filtration intervention | Urine samples were collected from each subject at 0h after the filtration intervention to quantify changes in urinary oxidative stress and inflammation biomarkers compared to baseline (i.e. before intervention). The urinary biomarkers to be analyzed include: malondialdehyde (MDA), 8-hydroxy-2' -deoxyguanosine (8-OHdG) and creatinine. The unit of the urinary biomarkers will be reported as micro molar/ milliliter. | At 0h after the filtration intervention | 
| Change in baseline urinary biomarkers of inflammation and oxidative stress at 6h after filtration intervention | Urine samples were collected from each subject at 6h after filtration intervention to quantify changes in urinary oxidative stress and inflammation biomarkers compared to baseline (i.e. before intervention). The urinary biomarkers to be analyzed include: malondialdehyde (MDA), 8-hydroxy-2' -deoxyguanosine (8-OHdG) and creatinine. The unit of the urinary biomarkers will be reported as micro molar/ milliliter. | 6h after filtration intervention | 
| Change in baseline urinary biomarkers of inflammation and oxidative stress at 24h after filtration intervention | Urine samples were collected from each subject at 24h after filtration intervention to quantify changes in urinary oxidative stress and inflammation biomarkers compared to baseline (i.e. before intervention). The urinary biomarkers to be analyzed include: malondialdehyde (MDA), 8-hydroxy-2' -deoxyguanosine (8-OHdG) and creatinine. The unit of the urinary biomarkers will be reported as micro molar/ milliliter. | 24h after filtration intervention | 
| Changes in baseline blood biomarkers of inflammation, oxidative stress and coagulation within 1h after filtration intervention | Blood samples were collected within 1h after filtration intervention for comparison of inflammatory and oxidative stress biomarkers to their baseline level (i.e. before the start of filtration intervention). Blood biomarkers that will be analyzed include: P-selectin, c-reactive protein, Von Willebrand factor and fibrinogen. The unit of the blood biomarkers will be reported as micro molar/ milliliter. | Within 1h after filtration intervention | 
| Changes in baseline blood biomarkers of inflammation, oxidative stress and coagulation right after filtration intervention | Blood samples were collected 24h after filtration intervention for comparison of inflammatory and oxidative stress biomarkers to their baseline level (i.e. before the start of filtration intervention). Blood biomarkers that will be analyzed include: P-selectin, c-reactive protein, Von Willebrand factor and fibrinogen. The unit of the blood biomarkers will be reported as micro molar/ milliliter. | 24h after filtration intervention | 
| Change in the duration of deep sleep on the first night and the second night of study participation | Duration of deep sleep was monitored by a sensor in a wristband on the first night and the second night of study participation | On the first night and the second night of study participation | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Air Pollution, Exposure Assessment, Filtration, Cardiovascular Outcomes, Respiratory Outcomes, Short-term Intervention