The overall objective of this study is to optimize, validate, and evaluate the effectiveness of strategies for reporting back environmental sampling results, with a focus on rural Native American populations and the balance between real-time and delayed feedback for both acute and chronic exposure concerns. The bioethical question of interest is: How does the information source (i.e., the messenger, format, and timing of education) impact the effectiveness of report-back strategies in rural tribal populations? This project is innovative because it addresses unanswered questions regarding the role that real-time exposure information plays in report-back strategies, with application to rural Native American populations. Aim 1: Optimization of Real-Time Report-Back Strategies for Rural Native American Research Participants. Previous work has involved environmental sampling data (indoor/outdoor PM2.5 and indoor radon) at households of N. Arapaho tribal members. Half of the participants received immediate exposure information from real-time, direct-reading displays while the other half only received final, delayed feedback with average data. The question remains as to whether the report-back strategies were as effective as desired. The hypothesis is that real-time exposure feedback will be more acceptable for short-term health outcomes whereas delayed feedback will be more acceptable for long-term health outcomes. Listening sessions and questionnaires will be used to evaluate prior approaches for both acute and chronic exposures, with a specific focus on our bioethical question. Aim 2: Validation of Optimized Report- Back Strategies for Rural Native American Research Participants. Based on the results of Aim 1, a series of vignettes will be developed that target the report-back strategies of interest (e.g., real-time exposure data for acute concerns, etc). These will be presented in 4-8 focus groups, with targeted discussions regarding the messenger type, format, and timing of education. The hypothesis is that the report back strategy that will be perceived as the most acceptable for all of the exposure scenarios will be in-person report-back by a tribal member, with education both before and after sampling. Aim 3: Evaluation of the Implementation of Exposure- Reduction Strategies from Report-Back of Environmental Exposures in Tribal Populations. Evaluation of the developed report-back approaches for long term (radon) and short-term (PM2.5) exposure risks will occur in two tribal populations: N. Arapaho and Utah Navajo. Reliability and generalizability will be tested to understand the extent to which individual tribes have unique needs and where techniques are more universal. Effectiveness of the strategies will be evaluated for the level of engagement with exposure-reduction activities, with a goal of building local capacity for management of evaluation activities into the future. The hypothesis is that real-time exposure feedback will result in more...