Research
Antioxidant airway responses following experimental exposure to wood smoke in man
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* Corresponding author: Anders Blomberg anders.blomberg@lung.umu.se
1 Department of Public Health and Clinical Medicine, Division of Medicine, Umeå University, Umeå, Sweden
2 Division of Respiratory Medicine and Allergy, Department of Medicine, University Hospital, Umeå, Sweden
3 Kings College London, MRC-HPA Centre for Environment and Health, School of Biomedical and Healthy Studies, King's College London, London, UK
4 Energy Technology and Thermal Process Chemistry, Umeå University, Umeå, Sweden
5 Division of Aerosol Technology, Lund University, Lund, Sweden
6 Department of Physics, Lund University, Lund, Sweden
7 Department of Analytical Chemistry, Arrhenius Laboratory, Stockholm University, Stockholm, Sweden
Particle and Fibre Toxicology 2010, 7:21 doi:10.1186/1743-8977-7-21
Published: 20 August 2010Abstract
Background
Biomass combustion contributes to the production of ambient particulate matter (PM) in rural environments as well as urban settings, but relatively little is known about the health effects of these emissions. The aim of this study was therefore to characterize airway responses in humans exposed to wood smoke PM under controlled conditions. Nineteen healthy volunteers were exposed to both wood smoke, at a particulate matter (PM2.5) concentration of 224 ± 22 μg/m3, and filtered air for three hours with intermittent exercise. The wood smoke was generated employing an experimental set-up with an adjustable wood pellet boiler system under incomplete combustion. Symptoms, lung function, and exhaled NO were measured over exposures, with bronchoscopy performed 24 h post-exposure for characterisation of airway inflammatory and antioxidant responses in airway lavages.
Results
Glutathione (GSH) concentrations were enhanced in bronchoalveolar lavage (BAL) after wood smoke exposure vs. air (p = 0.025), together with an increase in upper airway symptoms. Neither lung function, exhaled NO nor systemic nor airway inflammatory parameters in BAL and bronchial mucosal biopsies were significantly affected.
Conclusions
Exposure of healthy subjects to wood smoke, derived from an experimental wood pellet boiler operating under incomplete combustion conditions with PM emissions dominated by organic matter, caused an increase in mucosal symptoms and GSH in the alveolar respiratory tract lining fluids but no acute airway inflammatory responses. We contend that this response reflects a mobilisation of GSH to the air-lung interface, consistent with a protective adaptation to the investigated wood smoke exposure.