Project Summary “Role of Open Dumping And Open Burning Of Solid Waste In The Generation Of Microplastics And Products Of Incomplete Combustion On Tribal Lands” This research project addresses two critical issues in tribal lands caused by open dumping and burning: 1) potential generation of secondary microplastics which are currently under intense investigation worldwide due to their unknown health and environmental effects and 2) generation of volatile organic compounds (VOCs) which include a wide array of potential toxic substances. Open dumping and burning practices are common in tribal lands posing potential health to communities located nearby. Open dumping enables plague propagation, infection transmission, wildfire fire generation, greenhouse gas emission, water and solid ecosystems pollution, and bad odor emissions among other undesired effects. Open burning in addition to producing typical combustion products (e.g., carbon monoxide, carbon dioxide, water vapor, hydrogen sulfide) generates products of incomplete combustion. Products of incomplete combustion include greenhouse gases, reactive trace gases, VOCs, semi-VOCs, dioxins, and other toxic compounds, ashes, and particulate matter. Secondary microplastics are a potential product of incomplete combustion. Secondary microplastics are plastic materials generated by the fragmentation of larger plastic pieces. Despite the disparities in infrastructure that increase the likelihood of microplastics generation on tribal lands, their occurrence due to open burning practices and their effect on environment and health in tribal lands is largely unknown. We hypothesize that open dumping and burning practices generate and propagate microplastics and toxic VOCs in air, water, and soil enabling the exposure of communities located in proximity to waste disposal sites. The goal of the proposed project is to better understand the disparate environmental and health impacts of dumping and burning in tribal communities. We will partner with communities in Crow, Navajo, and Cheyenne River Sioux Tribe for this investigation. We propose the following specific aims: Specific Aim 1: Identify changes in physical and chemical properties of plastics from open burning activities and propagation pathways through the environment in lab scale experiments and field Specific Aim 2: Identify the potential exposure pathways and the environmental biophysical impacts of plastics from open burning activities in soil-plant-air systems. Specific Aim 3: Identify patterns in release of VOC, PAH, and dioxins released from open burning activities. Each tribal community likely has unique burning practices, thus the identification of both common and distinct patterns will help inform mitigation strategies that can be applied broadly or can be specifically tailored by community.