When wildfire smoke enters buildings, particles and chemicals can stick to indoor surfaces like floors and clothing, remaining indoors even after the smoke outside clears. The health risks from these contaminated surfaces are largely unknown, presenting a potential hidden danger in homes and workplaces. This project will study how smoke pollutants accumulate on common indoor materials, how these chemicals might change over time into new, possibly more toxic substances, and how people might be exposed to them through re-emission and contact with contaminated items. Understanding the interactions of smoke and indoor materials is essential for estimating the risks of smoke-exposed indoor surfaces. This work will contribute to safeguarding public health as it will improve understanding of these often-overlooked post-wildfire exposure risks indoors, help inform public health guidance and air quality policies and train the next generation of scientists to tackle this growing national environmental health challenge. This project seeks to establish fundamental understanding of the accumulation, chemistry, and subsequent human exposure risks from wildfire smoke constituents on indoor surfaces, a critical and scientifically unaddressed pathway. The project goals are threefold: first, to quantify the accumulation and post-event emission dynamics of organic compounds by determining mass-transfer and partitioning coefficients for smoke on authentic indoor materials; second, to elucidat