The majority of households in sub-Saharan Africa rely on solid biomass fuels (charcoal, wood, crop residues) for cooking. Women, as primary cooks, are exposed to harmful pollutants released from the inefficient combustion of these fuels, notably carbon monoxide (CO) and fine particulate matter (PM2.5). Preliminary studies link exposure to such biomass smoke with adverse pregnancy outcomes. In a cohort of Tanzanian pregnant women, the candidate will 1) determine predictors of high measured personal exposure to CO and PM2.5 during pregnancy, 2) identify histologic patterns of placental injury associated with high measured personal exposure to CO and/or PM2.5, and, 3) evaluate the association between measured personal exposure to CO and PM2.5 during pregnancy with birth weight (BW). This project innovatively combines personal air sampling for both CO and PM2.5 with placental examination to investigate exposure-response relationships between biomass combustion products and pregnancy outcome. Multivariate models will be created to identify predictors of high exposure and to evaluate the association between exposure and BW adjusting for other relevant determinants. Patterns of placental injury will be compared between high and low exposure groups to identify the potential pathophysiology underlying in utero injuries. Risk factors for adverse pregnancy outcome and reduced BW in resource-limited settings have focused largely on poor nutrition and infections with relatively little study of environmental perinatal risks. The candidate's proposed research has the potential to focus obstetric attention on a prevalent environmental exposure, household air pollution, and to shift environmental interventions to prenatal care packages. This research is integrally linked with the candidate's training program, which includes didactic coursework, guided readings, and structured mentorship in the areas of 1) environmental exposure assessment and analysis, 2) placental histopathology and biology, and 3) statistical techniques for complex exposure-response modeling using multivariate models. While the candidate's research efforts during the career development period will focus on air pollutants, techniques and methodologies they will learn will be translatable to the evaluation of obstetric risks associated with additional environmental pollutants to which these women are co-exposed. The candidate's ambition is to determine, and thereby catalyze a reduction in, the environmental burden faced by pregnant women in sub-Saharan Africa through independent, evidenced based research. 1 Public Health Relevance: Half of the world's households and over 80 percent of households in sub-Saharan Africa cook with solid biomass fuels (charcoal, wood, crop residues) generating smoke that is a complex mixture of harmful gases and particles. Women and children face the greatest health risks from such household air pollution and preliminary studies suggest that biomass smoke may be especially damaging during pregnancy. This project will characterize prenatal risks of biomass smoke so that interventions can be designed to adequately reduce exposure and thereby improve the health of pregnant women and their babies.