Jeff Angermann, Ph.D.;
Heather Holmes, Ph.D.
School of Community Health Sciences, University of Nevada, Reno, NV, United States,
Atmospheric Science Program, Department of Physics, University of Nevada, Reno, NV, United States.
The widespread use of solid biomass fuels in unimproved cookstoves has been associated with long term chronic health impacts that disproportionately affect women; however, the immediate effects of solid biomass fuel combustion on acute pulmonary function have not been thoroughly investigated. Cookstove fuel choices in many regions of the world are constrained by household wealth and natural resource availability. Solid fuel stoves that use wood, litterfall, and cow dung are common in rural Bangladesh, and cooking is typically performed by one or two female bari (household) members in a separate room from the main house. This study measured the acute respiratory impact of exposure to biomass fuel emissions for 15 females within the age range of 18-65 in rural Bangladesh.
Pulmonary function was measured with spirometry before and during cooking to assess changes in respiratory function associated with exposure to cookstove emissions. Specifically, the forced expiratory volume in one second (FEV1), forced vital capacity (FVC), FEV1 over FVC ratio, and peak expiratory flow (PEF) were measured and compared to time-weighted intensity of emissions of particulate matter of 2.5 micrometer or smaller average particle size (PM2.5). Cookstove emissions were characterized using continuous measurements PM2.5 concentrations at a 1-second time resolution using particulate monitors. Exposure metrics were calculated from the measured PM data to estimate the acute exposure to cookstove emissions for each study participant. The exposure estimates included the 3-minute maximum, 30-minute average, and the time weighted average PM2.5 concentration for the cooking time period.
Combustion of litterfall (i.e., leaves and twigs) and household material waste (i.e., paper and plastic wrappers) emissions yielded the highest 3-minute maximum PM2.5 concentrations. Larger or open cooking areas exhibited lower PM2.5 concentrations due to increased ventilation. Participants that have been preparing meals for more than 20 years in enclosed cooking areas with elevated PM2.5 concentrations displayed lower FEV1/FVC ratios, consistent with an enhanced risk of chronic obstructive pulmonary disease (COPD). Baseline-adjusted 3- and 10-minute maximum PM2.5 emissions were significantly associated with decrements in pulmonary function for this study population. Preliminary results also indicate that PEF decreased during cooking for 58% of the participants, and FEV1/FVC decreased during cooking for 67% of respondents.
Solid biomass-fueled cookstove emissions are associated with specific particulate matter signatures and decrements in instantaneous pulmonary function. These findings indicate justification for further research on pulmonary effects of solid biomass fuels.