ABSTRACT ECHO AWARE (ECHO in Agricultural Washington and Rural Environments) enriches the ECHO Program in two primary ways. 1) We will increase representation of rural and agricultural communities, particularly Latino families, in the ECHO Cohort. Rural children experience many health and environmental exposure disparities, yet are poorly represented in research and in the current ECHO Cohort. With deep community-engaged research ties to Washington’s agricultural Yakima Valley, our team is poised to enroll over 1000 pregnant individuals through partnership with their medical home and Federally Qualified Health Center (Yakima Valley Farm Workers Clinic). We also partner with Heritage University to involve Latino and Yakama Nation undergraduates and junior faculty to exchange perspectives regarding ECHO research practice and foster biomedical career development in this environmental justice community. Biospecimen collection will be led by a subteam with experience directing a biorepository for >10,000 pregnancies. 2) Our investigator team (diverse in career stage, scientific discipline, institution, cultural background) advances ECHO collaborative science in air pollution, airway health, and rural health. We propose a new cross-cohort Rural Health Workgroup plus a series of ECHO manuscripts to understand the health conditions and risk factors for under-resourced and minoritized communities in rural America, as well as best practices for engaging these hard-to-reach populations. A set of novel preconception analyses addresses widespread contaminants of concern for drinking water wells, an underdeveloped topic for ECHO. We also leverage decades of air pollution expertise to expand the air pollution exposures available for ECHO analyses and conduct solution-oriented research to directly inform U.S. regulatory policy and public health promotion programs. Our team contributes expertise in advanced methods for air pollution, including those for exposure mixtures. We also bring new national models for outdoor air pollutants of emerging concern to ECHO, including wildfire smoke (WFS) and ultrafine particulate matter (UFP). We first develop an improved national model for WFS to enable much-needed research on this climate-change driven catastrophe and lead manuscripts to describe impacts on US children. We then develop a new national model of UFP, an unregulated pollutant demonstrating high toxic potential in animal models yet with little epidemiological data. We also propose brief, low-burden extensions to the ECHO Protocol to better characterize rural chemical exposures as well as knowledge of the Air Quality Index (AQI) to explore disparities in access to this public health tool and evaluate its effectiveness in mitigating health effects. A proposed Wildfire Rapid Response Protocol will support natural experiment analyses of wildfire related health crises. Overall, ECHO AWARE builds on prior successes and insights gained as the ECHO PATHWAYS multi-cohort ...