Investigating the Health Benefits of Indoor Air Filtration Among Children: a Randomized Crossover Trial in Jiaozuo, China
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Enrollment
- 105
- Locations
- 2
- Primary Endpoint
- Changes of FEV1
Study Overview
Brief Summary
This study aims to explore the health benefits of air purifier on the impact of air pollutants on children's health.
Detailed Description
From April 2021 to December 2021, researchers conduct a randomized double-blind crossover trial on about 100 healthy children in Jiaozuo City, Henan Province. The children are divided into two groups according to their classes and alternated the use of true or sham purifiers devices, including air purifiers and fresh air ventilation. Air purifiers are installed in the classroom and bedrooms of the children. Fresh air ventilation is installed in the classroom. A total of 4 epidemiological surveys are conducted on the subjects, with an interval of 60 days or more. All participants and research staffs were blinded to the group assignment. In addition, air pollutant exposure monitoring, questionnaire surveys, physical examinations, and biological sample collection are conducted on the research subjects each time. The biological samples are further tested for the concentration levels of related biomarkers such as the respiratory system, cardiovascular system, metabolic system, and nervous system. Furthermore, comprehensive evaluation of children's behavioral ability is also carried out. Ambient PM2.5 and indoor PM2.5 exposure concentrations are monitored in the study.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Crossover
- Primary Purpose
- Prevention
- Masking
- Double (Participant, Investigator)
Eligibility Criteria
- Ages
- 10 Years to 12 Years (Child)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •10 ≤ 12 years old
- •Volunteer to participate in this study
Exclusion Criteria
- •Current and past medical history, including asthma, childhood diabetes, childhood hypertension, behavior-related diseases
- •Students who plan to transfer or move within six months
- •Unable to cooperate with follow-up
Outcomes
Primary Outcomes
Changes of FEV1
Time Frame: Baseline and at the end of each 60 days intervention period
The forced expiratory volume in 1 s (FEV1) is measured using a smart spirometer (Model A1, BreathHome, China) supervised by professional medical staff. Before the pulmonary function test, subjects will practice several times by themselves. During the examination, each subject stands and clamps the nose clip, and repeats the test, with the best result as the criterion. FEV1 reflect pulmonary function.
Changes of FVC
Time Frame: Baseline and at the end of each 60 days intervention period
The forced vital capacity (FVC) is measured using spirometer (Model A1, BreathHome, China). FVC reflects the expiratory resistance of large airways.
Changes of FEV1/FVC ratio
Time Frame: Baseline and at the end of each 60 days intervention period
The FEV1/FVC ratio is measured using smart spirometer (Model A1, BreathHome, China). FEV1/FVC ratio reflects the status of airway obstruction.
Changes of PEF
Time Frame: Baseline and at the end of each 60 days intervention period
The peak expiratory flow (PEF) is measured using smart spirometer (Model A1, BreathHome, China). PEF reflects airway patency and respiratory muscle strength.
Changes of FEF25-75%
Time Frame: Baseline and at the end of each 60 days intervention period
The forced expiratory flow at 25-75% of FVC (FEF25-75%) is measured using smart spirometer (Model A1, BreathHome, China). FEF25-75% reflects the small airway obstruction.
Changes of MEF75%
Time Frame: Baseline and at the end of each 60 days intervention period
The maximal expiratory flow at 75% of FVC (MEF75%) is measured using smart spirometer (Model A1, BreathHome, China). MEF75% reflects the terminal stage of expiratory flow rate.
Changes of MEF50%
Time Frame: Baseline and at the end of each 60 days intervention period
The maximal expiratory flow at 50% of FVC (MEF50%) is measured using smart spirometer (Model A1, BreathHome, China). MEF50% reflects the interim stage of expiratory flow rate.
Changes of MEF25%
Time Frame: Baseline and at the end of each 60 days intervention period
The maximal expiratory flow at 25% of FVC (MEF25%) is measured using smart spirometer (Model A1, BreathHome, China). MEF25% reflects the early stage of expiratory flow rate.
Changes of FeNO
Time Frame: Baseline and at the end of each 60 days intervention period
Use NIOX VERO Sensor to measure fractional exhaled nitric oxide (FeNO) as a biomarker for airway inflammation level. After deep breathing, the subjects gently inhaled into the device. The instrument showed FeNO level of the subjects.
Changes of FeCO
Time Frame: Baseline and at the end of each 60 days intervention period
Use Pico Smokerlyzer to measure fractional exhaled carbon monoxide (FeCO). After deep breathing, the subjects held their breath for 15 seconds and then gently inhaled into the device. The instrument showed FeCO level and the estimated value of carboxyhemoglobin in blood.
Changes of Blood Pressure
Time Frame: Baseline and at the end of each 60 days intervention period
The professional staffs wrap the BP cuff around the left upper arm of children to measure BP using the Omron electronic sphygmomanometers (OMROM, J751). BP is measured at 2-minute intervals, with a total of three measurements taken. If the difference of BP values between the last two measurements exceeds 5 mmHg, additional measurements are performed. Each child is allowed to measure BP at least three times and up to five times. The BP indicators includes SBP, DBP, MAP and PP.
Changes of heart rate variability
Time Frame: Baseline and at the end of each 60 days intervention period
The trained staffs conduct a 3-minute comprehensive assessment using the handheld electrocardiographic recorder-CarePatch (ECG-H01, Hangzhou Proton Technology Co., Ltd., China) to measured HRV. The time-domain indicators include standard deviation of all normal-to-normal intervals (SDNN), the root mean square of successive differences between adjacent normal cycles (rMSSD), the percentage of adjacent NN interval differences greater than 50 ms (pNN50); and the frequency-domain indicators include very low frequency (VLF), low frequency (LF), high frequency (HF), the ratio of LF to HF (LF/HF). To eliminate possible error, subjects are conducted by the same trained staff using the same instrument.
Changes of PR interval
Time Frame: Baseline and at the end of each 60 days intervention period
The trained staff use a 12-lead electrocardiogram (ECG) monitor to measure the participants' the interval of the beginning of the P wave to the beginning of the QRS complex (PR interval).
Changes of QRS duration
Time Frame: Baseline and at the end of each 60 days intervention period
The trained staff use a 12-lead electrocardiogram (ECG) monitor to measure the participants' the interval of the beginning of Q wave to the end of the S wave (QRS duration).
Changes of QT interval
Time Frame: Baseline and at the end of each 60 days intervention period
The trained staff use a 12-lead electrocardiogram (ECG) monitor to measure the participants' the interval from the onset of the QRS complex to the end of the T wave (QT interval).
Changes of QTc interval
Time Frame: Baseline and at the end of each 60 days intervention period
The trained staff use a 12-lead electrocardiogram (ECG) monitor to measure the participants' the QT correction for rate (QTc interval).
Changes of RV5
Time Frame: Baseline and at the end of each 60 days intervention period
The trained staff use a 12-lead electrocardiogram (ECG) monitor to measure the participants' the amplitude of the R-wave in lead V5 (RV5).
Changes of SV1
Time Frame: Baseline and at the end of each 60 days intervention period
The trained staff use a 12-lead electrocardiogram (ECG) monitor to measure the participants' the S-wave depth in lead V1 (SV1).
Changes of RV5+SV1
Time Frame: Baseline and at the end of each 60 days intervention period
The trained staff use a 12-lead electrocardiogram (ECG) monitor to measure the participants' the sum of the R-wave amplitude in lead V5 and the S-wave amplitude in lead V1(RV5+SV1).
Changes of academic performance
Time Frame: Baseline and at the end of each 60 days intervention period
The assessment of academic performance consists of standardised scores (maths, chinese and total) and the relative rank of the scores within grade. Standardised scores are converted from raw scores (with minimum value of 0 and maximum of 100) according to the number of exams and classes, indicating the position of the sample value in the normal distribution curve, with higher value showing better outcome. Rankings are converted from place rankings of raw values, with lower value showing better outcome.
Secondary Outcomes
- Changes of CRP(Baseline and at the end of each 60 days intervention period)
- Changes of 8-OHdG(Baseline and at the end of each 60 days intervention period)
- Changes of metabolites in exhaled breath condensate(Baseline and at the end of each 60 days intervention period)
- Changes of the role of alertness(Baseline and at the end of each 60 days intervention period)
- Changes of the role of orientation(Baseline and at the end of each 60 days intervention period)
- Changes of the role of conflict(Baseline and at the end of each 60 days intervention period)
- Changes of Wisconsin Card Sorting Test indicators(Baseline and at the end of each 60 days intervention period)
- Changes of the position total number(Baseline and at the end of each 60 days intervention period)
- Changes of the position number correct(Baseline and at the end of each 60 days intervention period)
- Changes of the position percentage correct(Baseline and at the end of each 60 days intervention period)
- Changes of the color total number(Baseline and at the end of each 60 days intervention period)
- Changes of the color number correct(Baseline and at the end of each 60 days intervention period)
- Changes of the color percentage correct(Baseline and at the end of each 60 days intervention period)
- Changes of the shape total number(Baseline and at the end of each 60 days intervention period)
- Changes of the shape number correct(Baseline and at the end of each 60 days intervention period)
- Changes of the shape percentage correct(Baseline and at the end of each 60 days intervention period)
- Changes of proteins in serum(Baseline and at the end of each 60 days intervention period)
- Changes in biomarkers identified from other omics(Through study completion, up to 10 years)
- Changes in other targeted biomarkers of interest(Through study completion, up to 10 years)
Investigators
Tiantian Li
professor
Centers for Disease Control and Prevention, China