Long-term indoor air conditioner filtration and cardiovascular health: A randomized crossover intervention study

Environ Int. 2017 Sep:106:91-96. doi: 10.1016/j.envint.2017.06.008. Epub 2017 Jun 15.


The association of short-term air pollution filtration with cardiovascular health has been documented. However, the effect of long-term indoor air conditioner filtration on the association between air pollution and cardiovascular health is still unclear. We recruited 200 homemakers from Taipei and randomly assigned 100 of them to air filtration or control intervention; six home visits were conducted per year from 2013 to 2014. The participants under air filtration intervention during 2013 were reassigned to control intervention in 2014. The air pollution measurements consisted of particulate matter less than or equal to 2.5μm in diameter (PM2.5) and total volatile organic compounds (VOCs); blood pressure was monitored for each participant during each visit. The following morning, blood samples were collected after air pollution monitoring. The blood samples were used to analyze biological markers, including high sensitivity-C-reactive protein (hs-CRP), 8-hydroxy-2'-deoxyguanosine (8-OHdG) and fibrinogen. Household information, including cleaning, cooking, and air conditioning, was collected by a questionnaire. Mixed-effects models were used to investigate the associations among air pollution measurements, blood pressure and biological markers. The results showed that increased levels of PM2.5 and total VOCs were associated with increased hs-CRP, 8-OHdG and blood pressure. The health variables were higher among participants in the control intervention phase than among those in the air filtration intervention phase. We concluded that air pollution exposure was associated with systemic inflammation, oxidative stress and elevated blood pressure. The long-term filtration of air pollution with an air conditioner filter was associated with cardiovascular health of adults.

Keywords: Air pollution; Blood pressure; Epidemiology; Indoor air filtration; Inflammation.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • 8-Hydroxy-2'-Deoxyguanosine
  • Adult
  • Aged
  • Air Conditioning*
  • Air Pollutants / adverse effects
  • Air Pollutants / analysis
  • Air Pollution, Indoor* / adverse effects
  • Air Pollution, Indoor* / analysis
  • Air Pollution, Indoor* / prevention & control
  • Biomarkers / blood
  • C-Reactive Protein / analysis
  • Cross-Over Studies
  • Deoxyguanosine / analogs & derivatives
  • Deoxyguanosine / blood
  • Female
  • Fibrinogen / analysis
  • Filtration*
  • Humans
  • Hypertension* / blood
  • Hypertension* / etiology
  • Hypertension* / prevention & control
  • Inflammation* / blood
  • Inflammation* / etiology
  • Inflammation* / prevention & control
  • Male
  • Middle Aged
  • Oxidative Stress / physiology
  • Particulate Matter / adverse effects
  • Particulate Matter / analysis
  • Volatile Organic Compounds / adverse effects
  • Volatile Organic Compounds / analysis


  • Air Pollutants
  • Biomarkers
  • Particulate Matter
  • Volatile Organic Compounds
  • 8-Hydroxy-2'-Deoxyguanosine
  • Fibrinogen
  • C-Reactive Protein
  • Deoxyguanosine