Oxidative Potential of Aerosol Emitted from Traditional Vs. Improved Cookstoves PDF Download

Author: Bradley Hugh Isenor
Publisher:
ISBN:
Category : Biomass
Languages : en
Pages : 0

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Book Description
Fine particulate matter (PM2.5) emitted from combustion processes can partake in cellular redox reactions and induce oxidative stress. This ability for PM2.5 to induce oxidative stress is known as its toxicity and is referred to as oxidative potential (OP). This poses a serious health risk for the ~3 billion people globally who continue to rely on biomass burning for their cooking needs as it is a significant source of indoor PM2.5. To combat the problem associated with traditional biomass burning cookstoves, 'improved' biomass burning cookstoves have been developed which have been shown to reduce the mass of PM2.5 generated. However, it is unknown whether the overall exposure to toxic chemicals contained in PM2.5 is reduced using these cookstoves as the adverse health effects of PM2.5 are better linked with OP than mass of PM2.5 inhaled. The goals of this study were to determine whether the OP of PM2.5 emitted from improved cookstoves was reduced and to determine what effect fuel type has on the OP of PM2.5. To test this, 4 fuel types (2 wood types and 2 charcoal types) were burned in 5 cookstoves (2 traditional and 3 improved) using the simmer-phase of the Water Boiling Test protocol to generate PM2.5 samples that were collected on quartz filters for analysis. The dithiothreitol (DTT) assay was employed to determine the OP of the PM2.5 and was split into 2 fractions, the water-soluble (WS) and total fraction. The DTT activity values were corrected using two variables, mass (OP(DPP/Mass)) and volume (OP(DPP/Volume)). The mass emitted from the 3 improved cookstoves were found to significantly reduce PM2.5 compared to the traditional stoves, consistent with previous studies. (OP(DPP/Volume)) was found to be more representative of the overall exposure to toxic PM2.5 emitted during a cooking event as it accounts for both intrinsic OP of the PM2.5 (toxicity per mass of PM2.5) and the mass emission of PM2.5. The (OP(DPP/Volume)) values were compared for all cooking methods and the wood fuel types were found to have the greatest (OP(DPP/Volume)) for each cookstove. Using the experimentally determined (OP(DPP/Volume)), example mitigation strategies were then suggested. Given the option to only switch cookstove or fuel type from the 3-stone with hardwood cooking method, a greater reduction in (OP(DPP/Volume)) can be achieved by switching from wood to coal (84% reduction) rather than 3-stone to improved stove (62% reduction). WS data was found to vary in its contribution to the total (OP(DPP/Volume)) from less than 15% to just below 75%, suggesting that the chemical composition of components that contributed to the OP of PM2.5 is dependent on cooking method.