Exposure to Wood Smoke is Associated with Increased Risk of Asthma and Respiratory Symptoms in a Honduran Population

Cho, B. H.; Castellanos, E.; Nguyen, E.; Oh, S.; Thakur, N.; Tarsi, J.; Koch, T.; Flores de Boquin, E.; Valladares, A.; Balmes, J.; Burchard, E.; Castro, M.; Galanter, J.

doi:10.1101/085407

bioRxiv · 10.1101/085407

Exposure to Wood Smoke is Associated with Increased Risk of Asthma and Respiratory Symptoms in a Honduran Population

Cho, B. H.·Castellanos, E.·Nguyen, E.·Oh, S.·Thakur, N.·Tarsi, J.·Koch, T.·Flores de Boquin, E.·Valladares, A.·Balmes, J.·Burchard, E.·Castro, M.·Galanter, J.

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Abstract

BackgroundExposure to environmental pollutants has been shown to be associated with asthma, but few studies have evaluated the effect of wood smoke on asthma and disease severity in a developing country, where use of stoves powered by solid fuels is a common practice.\n\nObjectiveIn a population in Olancho, Honduras, we evaluated the association between cooking fuel, stove type and asthma. We also evaluated the effects of these factors on asthma symptoms, lung function, and atopy.\n\nMethodsParticipants with physician-diagnosed asthma (n = 597) and controls without asthma (n = 429) were recruited from the Olancho province in Honduras. Participants were interviewed using a questionnaire and their baseline pulmonary function was measured using spirometry.\n\nResultsThe prevalence of use of wood as a cooking fuel was 66.9% in the study population, of which 42.1% of participants used wood as their only fuel. Use of wood as a cooking fuel was more prevalent among households with lower income, lower maternal education, and less urbanization. The prevalence of use of an open wood stove as the primary cooking stove among participants with asthma was 6.2% higher (95% CI 0.8 - 11.7%, p = .02) than among healthy controls. In a multiple logistic regression model, we identified a significant association between use of an open wood stove and asthma (OR = 1.80, 95% CI = 1.17 - 2.78, p = 0.007), compared to the referent (electric) stove category. Among participants with asthma, we identified a significant association between use of wood as cooking fuel and increased daytime respiratory symptoms (OR = 1.46, CI: 1.01 - 2.58, p = 0.046) and nocturnal symptoms (OR = 2.51, CI: 1.04 - 2.62, p = 0.04), though not with pulmonary function. Among control participants without asthma, use of wood as cooking fuel was associated with atopy (OR = 1.94, CI = 1.14 - 3.33, p = 0.015) and cough (OR = 2.22, CI = 1.09 - 4.88, p = 0.04).\n\nConclusionsUse of an open wood stove for cooking in a developing country appears to be a significant risk factor for asthma and respiratory symptoms. Exposure to wood smoke may play a role in atopic sensitization and respiratory symptoms, leading to the development of obstructive lung disease in susceptible individuals.

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Cho, B. H., Castellanos, E., Nguyen, E., Oh, S., Thakur, N., Tarsi, J., Koch, T., Flores de Boquin, E., Valladares, A., Balmes, J., Burchard, E., Castro, M., Galanter, J.. 2017-01-06. Exposure to Wood Smoke is Associated with Increased Risk of Asthma and Respiratory Symptoms in a Honduran Population. https://doi.org/10.1101/085407

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