Effects on airways of short-term exposure to two kinds of wood smoke in a chamber study of healthy humans

Inhal Toxicol. 2012 Jan;24(1):47-59. doi: 10.3109/08958378.2011.633281.


Introduction: Air pollution causes respiratory symptoms and pulmonary disease. Airway inflammation may be involved in the mechanism also for cardiovascular disease. Wood smoke is a significant contributor to air pollution, with complex and varying composition. We examined airway effects of two kinds of wood smoke in a chamber study.

Materials and methods: Thirteen subjects were exposed to filtered air and to wood smoke from the start-up phase and the burn-out phase of the wood-burning cycle. Levels of PM(2.5) were 295 µg/m(3) and 146 µg/m(3), number concentrations 140 000/cm(3) and 100 000/cm(3). Biomarkers in blood, breath and urine were measured before and on several occasions after exposure. Effects of wood smoke exposure were assessed adjusting for results with filtered air.

Results: After exposure to wood smoke from the start-up, but not the burn-out session, Clara cell protein 16 (CC16) increased in serum after 4 hours, and in urine the next morning. CC16 showed a clear diurnal variation. Fraction of exhaled nitric oxide (FENO) increased after wood smoke exposure from the burn-out phase, but partly due to a decrease after exposure to filtered air. No other airway markers increased.

Conclusions: The results indicate that relatively low levels of wood smoke exposure induce effects on airways. Effects on airway epithelial permeability was shown for the start-up phase of wood burning, while FENO increased after the burn-out session. CC16 seems to be a sensitive marker of effects of air pollution both in serum and urine, but its function and the significance need to be clarified.

Publication types

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

MeSH terms

  • Adult
  • Biomarkers
  • Breath Tests
  • Female
  • Humans
  • Inhalation Exposure / adverse effects*
  • Lung / drug effects*
  • Lung / metabolism
  • Male
  • Malondialdehyde / metabolism
  • Middle Aged
  • Nitric Oxide / metabolism
  • Oxidative Stress
  • Particle Size
  • Polycyclic Aromatic Hydrocarbons / analysis
  • Polycyclic Aromatic Hydrocarbons / toxicity*
  • Pulmonary Surfactant-Associated Protein A / metabolism
  • Pulmonary Surfactant-Associated Protein D / metabolism
  • Smoke / adverse effects*
  • Smoke / analysis
  • Surveys and Questionnaires
  • Uteroglobin / blood
  • Uteroglobin / urine
  • Volatile Organic Compounds / analysis
  • Volatile Organic Compounds / toxicity*
  • Wood*
  • Young Adult


  • Biomarkers
  • Polycyclic Aromatic Hydrocarbons
  • Pulmonary Surfactant-Associated Protein A
  • Pulmonary Surfactant-Associated Protein D
  • SCGB1A1 protein, human
  • Smoke
  • Volatile Organic Compounds
  • Nitric Oxide
  • Malondialdehyde
  • Uteroglobin