The impacts of traffic-related and woodsmoke particulate matter on measures of cardiovascular health: a HEPA filter intervention study

Occup Environ Med. 2015 Jun;72(6):394-400. doi: 10.1136/oemed-2014-102696. Epub 2015 Apr 20.


Background: Combustion-generated fine particulate matter (PM2.5) is associated with cardiovascular morbidity. Both traffic-related air pollution and residential wood combustion may be important, but few studies have compared their impacts.

Objectives: To assess and compare effects of traffic-related and woodsmoke PM2.5 on endothelial function and systemic inflammation (C reactive protein, interleukin-6 and band cells) among healthy adults in Vancouver, British Columbia, Canada, using high efficiency particulate air (HEPA) filtration to introduce indoor PM2.5 exposure gradients.

Methods: We recruited 83 healthy adults from 44 homes in traffic-impacted or woodsmoke-impacted areas to participate in this randomised, single-blind cross-over intervention study. PM2.5 concentrations were measured during two consecutive 7-day periods, one with filtration and the other with 'placebo filtration'. Endothelial function and biomarkers of systematic inflammation were measured at the end of each 7-day period.

Results: HEPA filtration was associated with a 40% decrease in indoor PM2.5 concentrations. There was no relationship between PM2.5 exposure and endothelial function. There was evidence of an association between indoor PM2.5 and C reactive protein among those in traffic-impacted locations (42.1% increase in C reactive protein per IQR increase in indoor PM2.5, 95% CI 1.2% to 99.5%), but not among those in woodsmoke-impacted locations. There were no associations with interleukin-6 or band cells.

Conclusions: Evidence of an association between C reactive protein and indoor PM2.5 among healthy adults in traffic-impacted areas is consistent with the hypothesis that traffic-related particles, even at relatively low concentrations, play an important role in the cardiovascular effects of the urban PM mixture.

Trial registration number: (NCT01570062).

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Air Pollutants* / analysis
  • Air Pollutants* / toxicity
  • Air Pollution, Indoor* / adverse effects
  • Air Pollution, Indoor* / analysis
  • Air Pollution, Indoor* / prevention & control
  • Biomarkers / analysis
  • British Columbia
  • C-Reactive Protein / analysis
  • Cardiovascular Diseases / etiology*
  • Cross-Over Studies
  • Endothelial Cells
  • Female
  • Filtration / methods
  • Humans
  • Inflammation / etiology
  • Inhalation Exposure / adverse effects*
  • Interleukin-6 / analysis
  • Male
  • Middle Aged
  • Motor Vehicles
  • Particulate Matter* / analysis
  • Particulate Matter* / toxicity
  • Smoke* / adverse effects
  • Vehicle Emissions* / analysis
  • Vehicle Emissions* / toxicity
  • Wood
  • Young Adult


  • Air Pollutants
  • Biomarkers
  • Interleukin-6
  • Particulate Matter
  • Smoke
  • Vehicle Emissions
  • C-Reactive Protein

Associated data