Atmospheric Environment xxx 2011 1e7 Contents lists available at ScienceDirect Atmospheric Environment journal homepage www elsevier com locate atmosenv Modeling indoor air pollution from cookstove emissions in developing countries using a Monte Carlo single box model Michael Johnson a Nick Lam a b Simone Brant a Christen Gray a David Pennise a a b Berkeley Air Monitoring Group 2124 Kittredge St 57 Berkeley CA 94704 USA Environmental Health Sciences University of California 725 University Hall Berkeley CA 94720 USA a r t i c l e i n f o a b s t r a c t Article history Received 29 December 2010 Received in revised form 18 March 2011 Accepted 21 March 2011 A simple Monte Carlo single box model is presented as a rst approach toward examining the relationship between emissions of pollutants from fuel cookstove combinations and the resulting indoor air pollution IAP concentrations The model combines stove emission rates with expected distributions of kitchen volumes and air exchange rates in the developing country context to produce a distribution of IAP concentration estimates The resulting distribution can be used to predict the likelihood that IAP concentrations will meet air quality guidelines including those recommended by the World Health Organization WHO for ne particulate matter PM2 5 and carbon monoxide CO The model can also be used in reverse to estimate the probability that speci c emission factors will result in meeting air quality guidelines The modeled distributions of indoor PM2 5 concentration estimated that only 4 of homes using fuelwood in a rocket style cookstove even under idealized conditions would meet the WHO Interim 1 annual PM2 5 guideline of 35 mg m 3 According to the model the PM2 5 emissions that would be required for even 50 of homes to meet this guideline 0 055 g MJ delivered 1 are lower than those for an advanced gasi er fan stove while emissions levels similar to lique ed petroleum gas 0 018 g MJ delivered 1 would be required for 90 of homes to meet the guideline Although the predicted distribution of PM concentrations median 1320 mg m 3 from inputs for traditional wood stoves was within the range of reported values for India 108e3522 mg m 3 the model likely overestimates IAP concentrations Direct comparison with simultaneously measured emissions rates and indoor concentrations of CO indicated the model overestimated IAP concentrations resulting from charcoal and kerosene emissions in Kenyan kitchens by 3 and 8 times respectively although it underestimated the CO concentrations resulting from wood burning cookstoves in India by approximately one half The potential overestimation of IAP concentrations is thought to stem from the model s assumption that all stove emissions enter the room and are completely mixed Future versions of the model may be improved by incorporating these factors into the model as well as more comprehensive and representative data on stove emissions performance daily cooking energy requirements and kitchen characteristics 2011 Elsevier Ltd All rights reserved Keywords Emission factors Biomass Air quality guidelines Stove testing 1 Introduction Emissions from solid fuel cookstoves used in the developing world result in indoor air pollutant concentrations orders of magnitude higher than those typically found in developed world environments The resulting exposures have been estimated to cause 3e4 of the global burden of disease Lopez et al 2006 Smith and Mehta 2003 with speci c health impacts including acute lower respiratory infections chronic obstructive pulmonary disorder increased Corresponding author Tel 1 510 649 9355 fax 1 510 295 2664 E mail address mjohnson berkeleyair com M Johnson blood pressure cataracts low birth weight tuberculosis and lung cancer amongst others Bruce et al 2000 McCracken et al 2007 Naeher et al 2007 Pokhrel et al 2005 Pope et al 2010 The relationships between stove performance metrics such as emission factors and thermal ef ciency and indoor pollutant concentrations however are not well characterized While many studies have demonstrated that improved stoves can reduce exposures by reducing emissions or venting emissions outdoors Armend riz Arnez et al 2008 Pennise et al 2009 Saksena et al 2003 efforts to directly link stove performance metrics to indoor air concentrations are lacking Modeling approaches to predict pollutant concentrations based on emission sources and environmental conditions are commonly 1352 2310 e see front matter 2011 Elsevier Ltd All rights reserved doi 10 1016 j atmosenv 2011 03 044 Please cite this article in press as Johnson M et al Modeling indoor air pollution from cookstove emissions in developing countries using a Monte Carlo single box model Atmospheric Environment 2011 doi 10 1016 j atmosenv 2011 03 044 2 M Johnson et al Atmospheric Environment xxx 2011 1e7 used tools in air pollution and climate studies Bond et al 2011 Hellweg et al 2009 Nicas 2008 yet have not been relied upon as tools for informing on the impact of improved stove projects Modeling approaches pose several potential bene ts including 1 estimating potential impacts on indoor air pollution concentrations before conducting expensive and time consuming eld studies 2 evaluating relative importance and impacts of critical stove performance parameters and environmental variables and 3 providing a means to set stove performance benchmarks or standards which are explicitly linked to air quality guidelines There is growing interest in setting standards for stove performance as part of international efforts to promote clean cookstoves Currently there are globally accepted performance standards for biomass cookstoves although the Shell Foundation Aprovecho Benchmarks have been used in laboratory testing for guidance and evaluation of stove design MacCarty et al 2010 These benchmarks however are not linked to air quality guidelines and are normalized to a standardized water boiling test which has been shown to be a poor predictor of emissions from normal stove use in homes Johnson et al 2008 2009 Roden et al 2009 This paper presents a rst approach toward addressing these needs with a simple Monte Carlo single box model which predicts indoor concentrations given a stove s emission performance and usage as well as kitchen characteristics Here we illustrate the utility of the model by presenting simulated distributions of IAP concentrations in kitchens based on a series of stove fuel scenarios comparing them with the