Prenatal chemical and childhood social exposures have compounding effects on children’s attention problems. To date, research on the etiology of attention problems has focused largely on endogenous, internal factors such as genetics, with little attention paid to the contribution of exogenous, environmental factors, such as neurotoxic exposures. In the parent award we detected significant associations between prenatal ETS exposure and the structure and function of children’s frontostriatal circuitry. Further, associations between prenatal ETS exposure and attention problems were mediated by changes in frontostriatal structure. These findings derive from the research and training program proposed in a Career Development Award that has supported the applicant towards becoming an NIH-funded independent investigator. This supplement funding will allow the Principal Investigator to study if COVID-19-related psychosocial stressors or acute stress symptoms magnify the effects of prenatal exposure to environmental tobacco smoke (ETS) on children’s brain function and attention. The data acquired with this supplemental funding will test the hypothesis that higher levels of COVID-19 pandemic-related psychosocial stressors or acute stress symptoms will amplify previously detected effects of prenatal ETS exposure on the structure and function of frontostriatal circuitry and attention problems that are subserved by this circuit. Through this Career Development Award, Dr. Margolis has developed expertise in using neuroimaging to study of the effects of neurotoxic environmental exposures on brain development and the manifestation of learning and attention problems. The current supplement to the parent award will allow Dr. Margolis to further develop her skills through acquiring and analyzing longitudinal functional magnetic resonance imaging (fMRI) data. In addition, this funding will support her in analyzing data from the new Environmental influences on Children’s Health Outcomes (ECHO) COVID-19 Acute Stress Questionnaire, which she co-authored. She will disseminate these methods for scoring and interpreting the Acute Stress questions in her role as Co-chair of the ECHO neurodevelopment working group. RELEVANCE: The current research will allow us to determine if pandemic-related psychosocial stressors and acute stress symptoms increase the behavioral and neurobiological effects of ETS. Such information may allow practitioners to treat attention problems through addressing acute stress symptoms and other pandemic- related psychosocial stressors (school and family factors). This approach may also generate data for public health messaging to mental health and pediatrics practitioners to consider the broad effects of increased stress and stressors on a range of other mental health problems during future pandemics.