The East Palestine Train Derailment Health Research Program - On February 3, 2023, a freight train carrying vinyl chloride (VC) and other chemicals derailed in East Palestine, OH, releasing toxic substances into the air, soil, surface water, and groundwater, with potential contamination of indoor air and drinking water. Approximately 40% of the 10-mile most impacted area extends into Beaver County, PA, just miles from East Palestine. Our preliminary data from current time-sensitive research grants(1R21ES036032, 1R21ES036033) reveal compelling evidence of potential health impacts, including elevated liver enzymes in a substantial portion of participants: 25% of women showing ALT levels above normal cutoffs (>19 U/L) and 16.7% of men exceeding normal ALT levels (>30 U/L). These findings are corroborated by abnormal FibroScan results in a subset of participants, suggesting hepatic impact consistent with VC exposure concerns and providing strong scientific justification for focused liver-thyroid axis assessment. To conduct comprehensive liver and thyroid function assessments in approximately 725 East Palestine community members to evaluate potential health impacts related to the train derailment exposure, with specific emphasis on liver-thyroid axis interactions and their implications for long-term health outcomes. Liver-Thyroid Axis Assessment: Standardized liver function testing including advanced FibroScan assessments to evaluate hepatic status in up to 400 participants during Year 1 will be performed. Comprehensive thyroid axis evaluations will be conducted to assess thyroid function at baseline (Year 1) and potential long-term effects (ideally in Year 4), capitalizing on the critical timing to detect delayed endocrine effects. Liver-thyroid functional relationships in the exposed population will be analyzed, leveraging the University of Pittsburgh's specialized FibroScan technology and liver disease expertise. Coordinating with designated university partners for phlebotomy services while ensuring optimal sample quality through rapid processing and transport, a comprehensive biospecimen analysis for liver and thyroid-related research will be established at UPMC. Clinical interpretation and evidence-based recommendations will be provided for participants with abnormal findings, supported by UPMC Center for Liver Care expertise. Innovation: This focused approach represents a scientifically-driven innovation leveraging the University of Pittsburgh's advanced FibroScan technology and specialized liver disease expertise to provide comprehensive hepatic assessment in a post-disaster environmental exposure context. Our emphasis on liver-thyroid axis interactions addresses a critical knowledge gap in understanding how vinyl chloride and associated chemical exposures affect interconnected endocrine and metabolic systems. The coordinated multi-institutional approach optimizes cost-efficiency while preserving time-sensitive biospecimen integrity essential for accurate endocrine and hepatic assessments. Impact: This study will provide critical data on liver and thyroid function in the East Palestine exposed population, directly informing clinical care for the 725 assessed participants and contributing essential knowledge to the broader understanding of chemical exposure health effects in disaster-affected communities. The comprehensive biospecimen repository will serve as a valuable resource for future environmental health research. The liver-thyroid axis focus will advance scientific understanding of interconnected metabolic and endocrine dysfunction following environmental chemical exposure, with implications extending beyond the East Palestine incident to inform future disaster response and environmental health assessment protocols.