HIPWOODS - Health Effects Related to Exposure to Particle Pollution From Woodburning Stoves
Condition: Airway Inflammation; Systemic Inflammation
MeSH terms: Inflammation
Study type: Interventional

Summary: 
      The study intends to focus on health effects and symptoms related to particle exposure from
      wood burning stoves

      The objective is to determine whether moderate exposure to particles from wood smoke in a
      real life situation causes an systemic inflammatory response in peripheral blood or in lower
      airways. 24 healthy subjects (normal healthy subjects and mild asthmatics to study the
      asthmatic response) is selected for the study. A randomized double blind crossover procedure
      will be followed with a PM exposure concentration of 200ug/m3, 400ug/m3 or clean air as the
      control exposure. Exposure will take place in a climate chamber using wood burning in an
      appropriate wood stove.
    

Detailed description: 
      Public health is concerned with the physical, mental and environmental health of communities
      and populations at risk for disease and injury. Generally, the determination of health
      effects associated with indoor and outdoor exposures is difficult since documented
      cause-and-effect relationships are rare and the exposure and dosage data is sparse.
      Information about actual human exposure to different types of pollution has several important
      uses, including informing risk assessments, helping predict the potential consequences of
      exposures, and developing exposure criteria for regulations and other public policy guidance.

      Wood-burning stoves have been a popular heating source for decades. Unfortunately,
      wood-burning stoves can emit substantial quantities of pollutants to outdoor and indoor air.
      Among the pollutants are: chlorinated dioxin, carbon monoxide, methane, volatile organic
      compounds (VOC), nitrogen oxides, polycyclic aromatic hydrocarbons (PAH), and fine
      particulate matter (PM10, PM2.5, fine and ultra fine particles). Recent studies indicate that
      the use of wood-burning stoves for heating of dwellings is one of the important outdoor
      particle sources [Glasius et al. 2004] in residential district in Denmark. This has resulted
      in an increase in public exposure to indoor and outdoor wood smoke related pollutants, which
      has prompted widespread concern about the adverse human health consequences that may be
      associated with wood smoke exposure.

      Air pollution is a major aggravation of respiratory symptoms and disease. Effects are
      decreases in pulmonary function and evidence of inflammation as well as suggestions of
      increases in chronic respiratory disease. Orozco-Levi et al. (2006) showed strong association
      between wood smoke exposure and obstructive pulmonary disease. Several studies have shown
      that especially the small particles, has an effect on airways, and that asthmatic subjects
      may be the group at greatest risk from air pollutants. The awareness of the impact of
      airborne particles, particularly fine and ultra fine particles, on health is growing. In
      recent years, exposure to fine and ultra fine airborne particles has been identified as an
      important factor affecting human health [Seaton et al., 1995; Schwartz et al., 1996;
      Oberdörster et al., 1994; Alvin et al., 2000]. Several researchers hypothesize that an
      increased mortality is associated with the particle levels prevailing in urban air [Jamriska
      et al., 1999; Dockery et al., 1993]. Mølhave et al (2000; 2005) have suggested that reactive
      short-lived compounds resulting from reactions between ozone and particulate matter cause
      indoor air quality complaints and objective health effects such as impaired lung functions.

      Particulate air pollution is also known to increase cardiovascular morbidity and mortality.
      Still the existing scientific knowledge and foundation for evaluating the underlying
      mechanisms and influence of particle exposure on human immune system are limited. Wood smoke
      particles, at levels that can be found in smoky indoor environments, seem to affect
      inflammation. Barregard et al observed a significant increase in S-Amyloid and Faktor
      VIII/vWf after 0, 3 and 20 hours of exposure to wood smoke. After 20 hours also and increase
      in Faktor VIII was registred. Surpise-lingly, an IL.-6 decrease was observed after 3 hours.
      [Barregard et al, 2006]. The particles may also act by increasing blood coagulation factors
      [Seaton et al 1995]. Both effects may be involved in the mechanisms whereby particulate air
      pollution affects cardiovascular morbidity and mortality.
    

Intervention name(s): Wood smoke particles
Intervention type(s): Other
Intervention description(s): Subjects are exposed at rest to the exposures for 3 h in our climate chamber
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Double (Participant, Investigator)
Keywords: Wood smoke; Health effects; Human; Airway inflammation; Cardiovascular effects