Air pollution dispersion from biomass stoves to neighboring homes in Mirpur, Dhaka, Bangladesh

Abstract

Background: Indoor air pollution, including fine particulate matter (PM 2.5 ) and carbon monoxide (CO), is a major risk factor for pneumonia and other respiratory diseases. Biomass-burning cookstoves are major contributors to PM 2.5 and CO concentrations. However, high concentrations of PM 2.5 (> 1000 μg/m 3 ) have been observed in homes in Dhaka, Bangladesh that do not burn biomass. We described dispersion of PM 2.5 and CO from biomass burning into nearby homes in a low-income urban area of Dhaka, Bangladesh. Methods: We recruited 10 clusters of homes, each with one biomass-burning (index) home, and 3-4 neighboring homes that used cleaner fuels with no other major sources of PM 2.5 or CO. We administered a questionnaire and recorded physical features of all homes. Over 24 h, we recorded PM 2.5 and CO concentrations inside each home, near each stove, and outside one neighbor home per cluster. During 8 of these 24 h, we conducted observations for pollutant-generating activities such as cooking. For each monitor, we calculated geometric mean PM 2.5 concentrations at 5-6 am (baseline), during biomass burning times, during non-cooking times, and over 24 h. We used linear regressions to describe associations between monitor location and PM 2.5 and CO concentrations. Results: We recruited a total of 44 homes across the 10 clusters. Geometric mean PM 2.5 and CO concentrations for all monitors were lowest at baseline and highest during biomass burning. During biomass burning, linear regression showed a decreasing trend of geometric mean PM 2.5 and CO concentrations from the biomass stove (326.3 μg/m 3 , 12.3 ppm), to index home (322.7 μg/m 3 , 11.2 ppm), neighbor homes sharing a wall with the index home (278.4 μg/m 3 , 3.6 ppm), outdoors (154.2 μg/m 3 , 0.7 ppm), then neighbor homes that do not share a wall with the index home (83.1 μg/m 3 ,0.2 ppm) (p = 0.03 for PM 2.5 , p = 0.006 for CO). Conclusion: Biomass burning in one home can be a source of indoor air pollution for several homes. The impact of biomass burning on PM 2.5 or CO is greatest in homes that share a wall with the biomass-burning home. Eliminating biomass burning in one home may improve air quality for several households in a community.