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A2281 - In Vitro Toxicity of Particulate Matter Derived from Biomass Cook Stoves Used in Developing Countries
Author Block: O. Uski1, G. Rankin2, R. Lindgren3, N. Lopez3, A. C. Blomberg2, A. Muala2, J. A. Bosson Damewood2, T. Sandstrom2; 1Department of Public Health and Clinical Medicine, Umeå University, Umea, Sweden, 2Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden, 3Department of Applied Physics and Electronics, Umeå University, Umeå, Sweden.
RATIONALE Particulate air pollution is a major public health concern worldwide. Globally, more than 2.4 billion people depend on biomass as a major source of energy for heating and cooking. COPD is common in women exposed to indoor wood smoke and exposure has been linked to increased risk of respiratory tract infections. The mechanisms by which biomass derived smoke affects human health are, however poorly understood. METHODS We investigated the toxicity of the particulate matter (PM) emissions from three types of cook stoves. The traditional 3-stone open fire using wood logs is the most simple and commonly used way of cooking in developing countries. As comparison, we studied two types of improved technologies, i.e. a natural draft (ND)- and a forced draft (FD) gasifier stoves, both using a pelletized wood fuel. While the ND system has been implemented to some extent, the FD technology, which requires electricity when operated, has so far been implemented less. Particulate samples for toxicological characterization were collected on teflon filters from diluted flue gases by using a five stage Dekati® gravimetric impactor. After methanol extraction and PM resuspension, the A549 human alveolar cell line was exposed to particulate samples from each cooking system for 24h (50-300µg/ml). Cell metabolic activity (CMA) was assessed with MTT assay and genotoxicity was determined using comet assay and cell cycle analysis. RESULTS The PM from the 3-stone fire was a more potent inducer of toxicological responses than the two more advanced cooking technologies. The 3-stone PM emissions was the only sample which decreased CMA. Significant increases in S-G2/M-cell cycle phase were detected both with 3-stone and ND stove PM samples. This effect can be considered as a sign of cell cycle arrest caused by DNA damage. All PM samples caused significant DNA fragmentation when compared to control (comet assay). However, the strongest effect was detected with the 3-stone cooking system. Beside higher total emissions of PM from the 3-stone stove, the emissions included considerably elevated concentrations of products of incomplete combustion, i.e. soot. CONCLUSIONS Clear differences in toxicity were demonstrated between the combustion technologies, which indicates that technological advancements have a crucial role in reducing harmful emissions. Moreover, advanced combustion technology have the potential to greatly reduce total PM emissions and human exposure, and the present study illustrates the need to assess also the specific toxicity of the emissions in different scenarios using different cook stove technologies and biomass fuels.