Indoor respirable particulate matter concentrations from an open fire, improved cookstove, and LPG/open fire combination in a rural Guatemalan community

Improved biomass cookstoves have the potential to reduce pollutant emission s and thereby reduce pollution exposure among populations in developing cou ntries who cook daily with biomass fuels. However, evaluation of such inter ventions has been very limited. This article presents results from a study carried out in 30 households in rural Guatemala. Twenty-four hour PM3.5 con centrations were compared over 8 months for three fuel/cookstove conditions (n = 10 households for each condition): a traditional open fire cookstove, an improved cookstove called the plancha mejorada, and a liquefied petrole um gas (LPG) stove/ open fire combination. Twenty-four hour geometric mean PM3.5 concentrations were 1560 mug/m(3) (n = 58; 95% C.I. 1310, 1850), 280 mug/m(3) (n = 59; 95% C.I. 240-320), and 850 mug/ m(3) (n = 60; 95% C.I. 68 0-1050) far the open fire, plancha, and LPG/open fire combination, respecti vely. A generalized estimating equation model showed a 45% reduction in PM3 .5 concentrations for the LPG/open fire combination as compared to the open fire alone. The difference approached significance (p < 0.0737). The planc ha showed an 85% reduction in PM3.5 concentrations as compared to the open fire (p < 0.0001). An analysis of the interaction of time with stove type s howed that the temporal trend in pollution did not significantly differ amo ng the three stove types. The reduced PM3.5 concentrations were maintained over time. Season did not affect pollutant concentrations. Of the two inter ventions, the plancha appears to offer the best prospects for achieving sub stantial reductions in indoor air pollution levels, although issues of cost and stove maintenance remain to be addressed.