Effects of woodsmoke exposure on airway inflammation in rural Guatemalan women.

• Main Authors: Michael J Guarnieri, Janet V Diaz, Chandreyi Basu, Anaite Diaz, Daniel Pope, Kirk R Smith, Tone Smith-Sivertsen, Nigel Bruce, Colin Solomon, John McCracken, John R Balmes
• Format: Article
• Language: English
• Published: Public Library of Science (PLoS) 2014-01-01
• Series: PLoS ONE
• Online Access: http://europepmc.org/articles/PMC3953023?pdf=render

BACKGROUND:More than two-fifths of the world's population uses solid fuels, mostly biomass, for cooking. The resulting biomass smoke exposure is a major cause of chronic obstructive pulmonary disease (COPD) among women in developing countries. OBJECTIVE:To assess whether lower woodsmoke exposure from use of a stove with a chimney, compared to open fires, is associated with lower markers of airway inflammation in young women. DESIGN:We carried out a cross-sectional analysis on a sub-cohort of participants enrolled in a randomized controlled trial in rural Guatemala, RESPIRE. PARTICIPANTS:We recruited 45 indigenous women at the end of the 18-month trial; 19 women who had been using the chimney stove for 18-24 months and 26 women still using open fires. MEASUREMENTS:We obtained spirometry and induced sputum for cell counts, gene expression of IL-8, TNF-α, MMP-9 and 12, and protein concentrations of IL-8, myeloperoxidase and fibronectin. Exhaled carbon monoxide (CO) and 48-hr personal CO tubes were measured to assess smoke exposure. RESULTS:MMP-9 gene expression was significantly lower in women using chimney stoves. Higher exhaled CO concentrations were significantly associated with higher gene expression of IL-8, TNF-α, and MMP-9. Higher 48-hr personal CO concentrations were associated with higher gene expression of IL-8, TNF- α, MMP-9 and MMP-12; reaching statistical significance for MMP-9 and MMP-12. CONCLUSIONS:Compared to using an open wood fire for cooking, use of a chimney stove was associated with lower gene expression of MMP-9, a potential mediator of airway remodeling. Among all participants, indoor biomass smoke exposure was associated with higher gene expression of multiple mediators of airway inflammation and remodeling; these mechanisms may explain some of the observed association between prolonged biomass smoke exposure and COPD.