The Use of Air Cleaners to Mitigate Cardiopulmonary Health Impact of Indoor Exposure to Particles and Phthalates
Condition: Blood Pressure; Lung Function; Inflammation; Oxidative Stress
MeSH terms: Inflammation
Study type: Interventional

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.
    

Intervention name(s): Air cleaner use method 1; Air cleaner use method 2
Intervention type(s): Behavioral; Behavioral
Intervention description(s): All interventions in the first cohort will start at noon on Tuesday or Thursday and continue to the next morning of Tuesday or Thursday.; All interventions in the second cohort will start from the beginning to the end of smog episodes.
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Prevention
Keywords: particulate matter; phthalates; cytokines; chemokines; epigenetics; DNA methylation; peripheral blood mononuclear cells; immune function