Linking Household Energy Use with Indoor Air Quality

Abstract

The WHO Indoor Air Quality Guidelines (AQGs) for Household Fuel Combustion used a model to derive the emission rates required to meet WHO intermediate targets and AQGs for PM2.5 and CO. The model used was a single zone model, a relatively simple construct which requires few assumptions and has been widely applied in air pollution and climate research. A probabilistic Monte Carlo approach was used to account for variability in physical characteristics and energy demands of households. Specifically, the model used input distributions of kitchen volumes, ventilation rates, daily usage times, and emissions capture efficiency (for chimney stoves) to produce output distributions of mean 24 hour PM2.5 and CO concentrations. The resulting output distributions were then compared with WHO targets and AQGs to estimate the percentage of homes that would meet or exceed these targets and AQGs. Emissions rates of the best-performance solid biomass technologies, when measured under controlled laboratory conditions, suggest that improvements in PM2.5 emission rates are needed for 60% of homes to meet the interim-1 annual AQG for PM2.5 (35?g m^-3^). Meeting the final PM2.5 AQG (10?g m^-3^) would require substantially greater emissions rate improvements for solid biomass stoves. Emission rates of solid biomass stoves measured during normal use in homes are greater than those measured in the laboratory, and these stoves typically do not fully displace traditional stove use, indicating a considerable challenge for meeting WHO targets and AQGs with these technologies. Use of clean-burning gas and liquid fuels such as LPG, natural gas, biogas, and ethanol, as well as electricity, however, represent technologies which can provide high levels of protection immediately.