Research on the optimization of secondary air-injection from the Cookstoves Group at LBNL has recently been accepted for publication in Environmental Science and Technology. This research parametrically investigates the effect of secondary air injection on the mass and size distribution of PM emitted during solid biomass combustion using a modular, experimental wood-burning cookstove platform. The results show that PM emissions are highly sensitive to secondary air injection flow rate and velocity, and that increasing the total flow rate of secondary air may cause localized flame quenching that increases particle emissions. Therefore, biomass cookstoves that implement secondary air injection should be carefully optimized and validated to ensure that PM emission reductions are achieved throughout the particle size range. The published paper can be found here and will be posted soon to Publications.