The Use of Air Cleaners to Mitigate Cardiopulmonary Health Impact of Indoor Exposure to Particles and Phthalates

NCT ID: NCT03500614

Last Updated: 2021-10-15

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 57 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2017-11-14
• Study Completion Date: 2018-12-01

Brief Summary

This study aims to evaluate whether a short-term intervention strategy using air cleaner reduces indoor exposure to airborne particles (particulate matter with an aerodynamic diameter ≤2.5μm, PM2.5) and phthalates and improves cardiopulmonary health among Chinese healthy adults based on a randomized double-blinded crossover trial.

Detailed Description

The randomized double-blind crossover trial includes two cohorts with different intervention and health examination settings and will be conducted in Beijing, China between November 2017-May 2018.

The first cohort plans to include 70 healthy college students who live in school dormitories, which were randomized into two dormitory groups to receive either true or sham air cleaner treatment for 1 week and then alternate the treatment after a wash out interval of at least 2 weeks (But in the enrollment, only 57 students were recruited actually). All participants and research staff are blinded to the group assignment. All participants are encouraged to stay in the dormitory with windows/doors tightly closed throughout the 1-week treatment period as far as possible, whereas necessary outdoor activities such as attending classes and dining in school canteens are allowed. All interventions will start at noon on Tuesday or Thursday and continue to the next morning of Tuesday or Thursday to avoid issues related to diurnal variation. Real-time PM2.5 concentrations will be measured using portable monitors and airborne PM2.5 mass samples will be collected in air filters throughout the treatment period. Air and fine particle phase phthalates samples will be collected using glass sampling tube filled with XAD2 macroporous resin and PM2.5 air filters respectively during the last day (24 hours) of the treatment period. Health variables, including blood pressure, lung function, fractional exhaled nitric oxide (FeNO), will be evaluated and biological samples including morning urine and fasting blood will be collected immediately after the completion of each treatment period. Efficacy of air cleaner treatment to reduce indoor exposure to particles and phthalates and related improvements in cardiopulmonary health variables will be evaluated using professional statistical methods.

The second cohort plans to include 30 healthy college students who will undergo extended treatment period covering the start, peak and end phases of smog episodes occurring in Beijing (To avoid dropout, 32 students were initially recruited). All interventions will start from the beginning to the end of typical smog episodes. PM2.5 exposure monitoring as detailed above will be performed throughout the treatment period and repeated health examinations will be conducted at time points corresponding to the start, peak and end phases of the smog episodes. Efficacy of air cleaner treatment to reduce indoor exposure to PM2.5 and related improvements in cardiopulmonary health variables throughout the smog episodes will be evaluated using professional statistical methods.

Conditions

Blood Pressure; Lung Function; Inflammation; Oxidative Stress

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: PREVENTION
• Blinding Strategy: DOUBLE

Study Groups

Cohort 1

Participants (n=57) will receive either true or sham air cleaner treatment for 1 week and then alternate the treatment after a wash out interval (Air cleaner use method 1). Exposure monitoring for PM2.5 will continue throughout the treatment period and air and fine particle phase phthalates samples will be collected during the last day (24 hours) of the treatment period; and health variables will be measured and biological samples will be collected immediately after the completion of each intervention period.

Group Type: EXPERIMENTAL

Air cleaner use method 1

Intervention Type: BEHAVIORAL

All interventions in the first cohort will start at noon on Tuesday or Thursday and continue to the next morning of Tuesday or Thursday.

Cohort 2

Participants (n=32) will undergo extended treatment period covering the start, peak and end phases of smog episodes in Beijing, with either true or sham air cleaner treatment and then alternate the treatment after a wash out interval (Air cleaner use method 2). Exposure monitoring for PM2.5 will continue throughout the treatment period and repeated health examinations will be conducted at time points corresponding to the start, peak and end phases of the smog episodes.

Group Type: EXPERIMENTAL

Air cleaner use method 2

Intervention Type: BEHAVIORAL

All interventions in the second cohort will start from the beginning to the end of smog episodes.

Interventions

Air cleaner use method 1

All interventions in the first cohort will start at noon on Tuesday or Thursday and continue to the next morning of Tuesday or Thursday.

Intervention Type: BEHAVIORAL

Air cleaner use method 2

All interventions in the second cohort will start from the beginning to the end of smog episodes.

Intervention Type: BEHAVIORAL

Eligibility Criteria

Inclusion Criteria

• Healthy college students aged between 18 and 30 years old;
• Will stay within the central urban area of Beijing over the entire study including the wash-out period;
• BMI <30 kg/m3.

Exclusion Criteria

• Current or ever smokers;
• A history of chronic respiratory diseases;
• A history of chronic cardiovascular diseases;
• Acute infections;
• Medication use in recent one month;
• Leave Beijing during the intervention.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 30 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Peking University

OTHER

Sponsor Role: lead

Responsible Party

Jing Huang

Assistant Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Jing Huang, PhD

Role: PRINCIPAL_INVESTIGATOR

Peking University

Shaowei Wu, PhD

Role: PRINCIPAL_INVESTIGATOR

Peking University

Locations

Department of Occupational & Environmental Health Sciences, School of Public Health, Peking University

Beijing, , China

Countries

China

Other Identifiers

2017YFC0211601

Identifier Type: OTHER_GRANT

Identifier Source: secondary_id

2016YFC0207103

Identifier Type: OTHER_GRANT

Identifier Source: secondary_id

2017095

Identifier Type: -

Identifier Source: org_study_id