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NCT Number: NCT05016271

Health Benefits of Air Purifiers in Primary School Students

This study aims to explore changes in cardiopulmonary function and other health indicators in primary school students with the intervention of air purifiers on a randomized controlled trial.

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This study is active but is not currently recruiting participants.

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Key information

Conditions

Cardiopulmonary Function Child

Age range

8 year–12 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Department of Environmental Health, School of Public Health, Fudan University

Shanghai, Shanghai Municipality, 200032, China

About this study

The investigators will conduct a randomized controlled trial among 110 healthy children in Jiaozuo city, Henan, China. The eligible children will be divided into two groups according to their classes and randomly receive interventions of either true or sham air purifiers. The air purifiers devices in classroom [air purifiers and fresh air ventilation systems] will operate during the school time and the devices in bedrooms (air purifiers) operate during the home time in the intervention period. All the participants and investigators will be blinded to the group assignment. Epidemiological questionnaires (i.e., basic characteristics, eating habits, daily schedule, etc.) will be conducted and health indicators (i.e., blood pressure, pulmonary function indicators, fractional exhaled nitric oxide, and fractional exhaled carbon monoxide) and biological specimens (i.e., morning urine, venous blood, exhaled breath condensate, and feces) will be evaluated and collected at baseline and after the completion of intervention period (4 months anticipated).

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age of between 8 and 12 years old
  • Males and female of ethnic Han
  • Subjects who have no plans to change classroom during the intervention period
  • Subjects who staying in Jiaozuo city during the intervention period

Exclusion criteria

  • Subjects with asthma, childhood diabetes, childhood hypertension, and behavioral disorders
  • Subjects who plan to transfer or move offsite within six months
  • Subjects who decorated or plan to decorate home within six months
  • Subjects with smokers in the household

Treatment and study plan

Air purifier and fresh air ventilation systems with high-efficiency particulate air (HEPA) filters

Behavioral

This group will receive an intervention of true air purifiers. The air purifiers in classroom (air purifiers and fresh air ventilation systems with HEPA filters) will operate during the school time and the air purifiers in bedrooms (air purifiers with HEPA filters) operate during the home time in the intervention period (4 months anticipated).

Air purifier and fresh air ventilation systems without high-efficiency particulate air (HEPA) filters

Behavioral

This group will receive an intervention of sham air purifiers. The air purifiers in classroom (air purifiers and fresh air ventilation systems without HEPA filters) will operate during the school time and the air purifiers in bedrooms (air purifiers without HEPA filters) operate during the home time in the intervention period (4 months anticipated).

Primary outcomes

  1. Changes of heart rate variability

    Time frame: Baseline and after the completion of intervention period (4 months anticipated)

    Nihon Kohden Electrocardiograph and Carepatch Electrocardiogram are used to measure heart rate variability, including standard deviation of all normal-to-normal R-R intervals (SDNN), standard deviation of sequential five-minute R-R interval means (SDANN), root-mean-square difference of successive normal R-R intervals (RMSSD), low frequency (LF), and high frequency (HF) in intervention and control groups. To eliminate possible errors, measurements are conducted by the same trained staff using the same instrument.

  2. Changes of forced expiratory volume in 1 s (FEV1)

    Time frame: Baseline and after the completion of intervention period (4 months anticipated)

    The pulmonary function measures are performed by the professional medical device. Before the pulmonary function test, subjects practice several times with the guidance of professional staff. During the examination, each subject in a sitting position and clamp the nose clip, and repeat the test, with the best result as the criterion.

  3. Changes of forced vital capacity (FVC)

    Time frame: Baseline and after the completion of intervention period (4 months anticipated)

    The pulmonary function measures are performed by the professional medical device. Before the pulmonary function test, subjects practice several times with the guidance of professional staff. During the examination, each subject in a sitting position and clamp the nose clip, and repeat the test, with the best result as the criterion.

  4. Changes of forced expiratory volume in 1 s (FEV1) / forced vital capacity (FVC) ratio

    Time frame: Baseline and after the completion of intervention period (4 months anticipated)

    The pulmonary function measures are performed by the professional medical device. Before the pulmonary function test, subjects practice several times with the guidance of professional staff. During the examination, each subject in a sitting position and clamp the nose clip, and repeat the test, with the best result as the criterion.

  5. Changes of peak expiratory flow (PEF)

    Time frame: Baseline and after the completion of intervention period (4 months anticipated)

    The pulmonary function measures are performed by the professional medical device. Before the pulmonary function test, subjects practice several times with the guidance of professional staff. During the examination, each subject in a sitting position and clamp the nose clip, and repeat the test, with the best result as the criterion.

  6. Changes of fractional exhaled nitric oxide (FeNO) levels

    Time frame: Baseline and after the completion of intervention period (4 months anticipated)

    A NIOX VERO Sensor is used to measure fractional exhaled nitric oxide (FeNO) as a biomarker for airway inflammation. After deep breathing, the subjects gently inhaled into the device. The instrument shows FeNO level of the subjects.

  7. Changes of fractional exhaled carbon monoxide (FeCO) levels

    Time frame: Baseline and after the completion of intervention period (4 months anticipated)

    Use PICO to measure fractional exhaled carbon monoxide (FeCO) as a biomarker for cardiovascular risk. After deep breathing and holding the breath for 15 seconds, the subjects gently inhaled into the device. The instrument shows FeCO level of the subjects.

  8. Changes of blood pressure

    Time frame: Baseline and after the completion of intervention period (4 months anticipated)

    Using Omron blood pressure monitor to measure the systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse pressure for each subject by the trained staff using the same instrument.

Secondary outcomes

  1. Changes of C-reactive protein (CRP)

    Time frame: Baseline and after the completion of intervention period (4 months anticipated)

    Detect the concentration of C-reactive protein (CRP) in blood sample to examine the different level of inflammation between the groups of intervention and control.

  2. Changes of 8-hydroxydeoxyguanosine (8-OHdG)

    Time frame: Baseline and after the completion of intervention period (4 months anticipated)

    Detect the concentration of 8-hydroxydeoxyguanosine (8-OHdG) in urine sample of groups of intervention and control. 8-OHdG is a biomarker for DNA oxidative damage.

  3. Changes of persistent response (PR)

    Time frame: Baseline and after the completion of intervention period (4 months anticipated)

    Examine persistent response (PR) as the index to test the focus ability of children. The test is performed by the Wisconsin Card Sorting Test (WCST) through a computer, and the index reflects the ability of cognitive transfer. The normal value is less than or equal to 27.

  4. Differences in metabolite levels detected in metabolomics between groups of intervention and control.

    Time frame: Baseline and after the completion of intervention period (4 months anticipated)

    Mass spectrometry-based serum metabolomics is non-targeted. The study is to explore the differential metabolites in blood/urine/exhaled breath condensate (EBC) samples of the groups of intervention and control.

Sponsors and collaborators

Lead sponsor

Fudan University

Other

Registry information

Official study title

Health Benefits of Air Purifiers in Primary School Students: A Randomized Controlled Trial

Important dates

Study start
2021
Primary completion
2022
Study completion
2026
First posted
Aug 23, 2021
Registry last updated
Feb 27, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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