Antioxidant airway responses following experimental exposure to wood smoke in man.
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.
Sehlstedt
Maria
M
Department of Public Health and Clinical Medicine, Division of Medicine, Umeå University, Umeå, Sweden.
Dove
Rosamund
R
Boman
Christoffer
C
Pagels
Joakim
J
Swietlicki
Erik
E
Löndahl
Jakob
J
Westerholm
Roger
R
Bosson
Jenny
J
Barath
Stefan
S
Behndig
Annelie F
AF
Pourazar
Jamshid
J
Sandström
Thomas
T
Mudway
Ian S
IS
Blomberg
Anders
A
D000328:Adult; D000975:Antioxidants / Q000378:metabolism*; D004311:Double-Blind Method; D005260:Female; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D008168:Lung / Q000378:metabolism*; D008297:Male; D052638:Particulate Matter / Q000633:toxicity*; D012906:Smoke / Q000009:adverse effects*; D014934:Wood
D000975:Antioxidants; D052638:Particulate Matter; D012906:Smoke; D005978:Glutathione