Approximately 3 billion people rely on solid fuel combustion to meet basic domestic energy needs. Many households rely on traditional, inefficient and poorly vented indoor cook stoves to meet these needs, which can result in extremely high indoor air pollution concentrations. Improved stove designs have the potential to substantially reduce pollutant emissions and indoor air pollution exposures. However, quantitative and longitudinal assessments of improved stoves are limited. Indoor air pollution from biomass and coal smoke is estimated to account for approximately 1.6 million premature deaths per year worldwide, representing about 3% of the global disease burden. These estimates are based primarily on respiratory disease effects. Very few studies have evaluated the cardiovascular effects of indoor biomass burning. Given the ubiquity of biomass smoke exposures around the world and the increasing prevalence of cardiovascular disease, further study of this relationship is needed in order to fully assess the burden. We recently completed data collection for a cook stove intervention study in 123 households in a semi-rural area of Nicaragua. Here we propose to conduct a comprehensive analysis of the previously collected data, and add a new laboratory analysis of stored dried blood spot samples. Our central hypothesis is that use of the improved stoves will result in lower air pollution concentrations and improved health status compared to the use of a traditional stove. To evaluate this hypothesis, we propose 3 Specific Aims: (1) Measure markers of inflammation in dried blood spot samples collected from primary female cooks at baseline and in Year 2 in the Nicaragua cohort;(2) Evaluate factors related to adoption of the improved stove, and then examine improved stove use in relation to changes in health indicators (inflammatory markers, heart rate, blood pressure, lung function, and symptoms);(3) Compare air pollution concentrations of indoor fine particulate matter and indoor and personal carbon monoxide at baseline and Year 2 (among a subsample of the population), and evaluate the relationship of change in pollution concentrations with change in health outcomes. Cardiovascular disease is a growing and under studied disease in developing countries, and it is the leading cause of death in Nicaragua. This project will contribute not only to the knowledge of the relationship between cook stove use and indicators of cardiovascular disease, but this novel use of the dried blood spot method can also demonstrate the feasibility and utility of the method for measuring sub-clinical markers of cardiovascular disease risk in developing countries. Evidence supporting associations between indoor pollutants and indicators of cardiovascular health could substantially increase the previously estimated burden of disease due to cook stove smoke. Furthermore, longitudinal evaluations of improved cook stove interventions, and factors related to improved stove adoptions, are necessary to encourage and justify similar intervention and stove change-out programs, especially in parts of the world where biomass is the preferred or necessary cooking fuel. PUBLIC HEALTH RELEVANCE: Approximately 3 billion people rely on solid fuel combustion to meet basic domestic energy needs. Indoor air pollution from biomass burning accounts for approximately 1.6 million premature deaths per year worldwide, representing about 3% of the global disease burden. The proposed work will examine the impact of an improved indoor cook stove intervention on indicators of respiratory and cardiovascular health in a developing country.