Background and Rationale: Per- and polyfluoroalkyl substances (PFAS) are a class of synthetic chemicals widely used in industrial and consumer products due to their water- and oil-repellent properties, as well as durability and resistance to heat. Because PFAS are highly persistent in the environment and human body, they are often referred to as "forever chemicals." PFAS are found in food packaging, non-stick cookware, stain- and water-resistant textiles, personal care products, carpets, and other household materials. Human exposure occurs primarily through contaminated drinking water, diet, consumer products, and inhalation of household dust. Nearly all individuals tested in the United States have measurable levels of PFAS in their blood. Chronic PFAS exposure has been linked to adverse health outcomes, including cardiometabolic disorders (hypertension, dyslipidemia, vascular disease, cardiac toxicity), endocrine and thyroid dysfunction, immune system impairment, congenital anomalies, liver disease, cancer, and developmental effects. Rural communities are disproportionately affected by PFAS exposure due to multiple factors, including reliance on small water utilities, private wells, proximity to industrial or military sites, and agricultural contamination from sludge-based fertilizers. These populations often face compounded health disparities, such as limited access to preventive healthcare, lower environmental health literacy (EHL), and higher baseline rates of chronic disease. National guidance, such as from the US National Academies of Sciences, Engineering, and Medicine (NASEM), recommends that individuals with elevated PFAS levels receive clinical monitoring for dyslipidemia and other health risks. However, rural residents and many healthcare providers lack practical, accessible tools to understand, interpret, and act upon PFAS exposure information. Previous research demonstrates that biomonitoring report-back-providing individuals with their personal chemical exposure results accompanied by actionable recommendations-can increase environmental health literacy, promote risk-reduction behaviors, and improve wellness outcomes without causing undue stress. Million Marker (MM), a direct-to-consumer biomonitoring company, has demonstrated success with report-back interventions for endocrine-disrupting chemicals (EDCs), showing improvements in EHL, behavior, and urinary biomarker levels. Leveraging this expertise, this study aims to develop and pilot an educational and actionable PFAS blood test report-back intervention for rural adults, in collaboration with healthcare providers, to improve knowledge, behavior, and wellness outcomes. Study Objectives: The primary goal of this observational study is to assess whether personalized PFAS blood test results combined with educational and actionable report-back materials can: 1. Increase environmental health literacy (EHL) regarding PFAS exposure and associated health risks. 2. Enhance readiness to reduce PFAS exposure and adoption of risk-reduction behaviors. 3. Improve wellness indicators, including stress reduction, sleep quality, and perceived control over health. Secondary objectives include evaluating usability and comprehension of the report-back materials, identifying barriers to behavioral change, and informing the design of a future Phase II randomized trial and scalable public health intervention. Study Design: This is a prospective, single-group observational study utilizing pre- and post-intervention surveys to evaluate outcomes. Participants will serve as their own control, with baseline measurements compared to post-intervention responses. The study incorporates both quantitative and qualitative methodologies to develop, refine, and evaluate the PFAS report-back intervention. Sample Size: The study will recruit 110 adult participants residing in rural areas. Sample size calculations, based on previous report-back interventions, ensure at least 80% power to detect meaningful changes in EHL and readiness to act, accounting for up to 16% attrition. Population and Eligibility: Inclusion criteria includes age ≥ 18 years, residing or working in a rural area of Nevada (verified via zip code and Health Resources and Services Administration classification), ability to understand English and complete study activities, and willingness to provide mail-in blood sample and complete pre- and post-surveys. Diversity and Representation: The study aims for at least 30% representation from minority populations, including Hispanic and Black residents, reflecting Nevada's rural demographics. Procedures: 1. Recruitment and Consent: Participants will be recruited via the Healthy Nevada Project, which maintains a population cohort of over 50,000 residents, including a substantial rural subset. Recruitment methods include targeted mailings and electronic communications. Interested participants will review study information and provide informed consent electronically. 2. Baseline Assessment: Participants will complete a pre-intervention survey capturing: demographics (age, gender, race/ethnicity, education, income), environmental health literacy (general and PFAS-specific knowledge, attitudes, and behaviors), lifestyle and exposure behaviors (diet, water use, product use, cleaning habits, and household exposures), and wellness measures (stress, sleep, and self-assessed health status). 3. PFAS Blood Sample Collection: Participants will receive a mail-in blood spot collection kit through Relentless Health. Instructions and a short video will guide participants through self-collection. Blood samples will be returned to the lab for PFAS biomarker analysis. 4. Report-Back Intervention: Each participant will receive a personalized PFAS report summarizing: individual PFAS biomarker concentrations, comparison with national reference data and NASEM guidance levels, identification of likely exposure sources, tailored, practical recommendations for reducing PFAS exposure (e.g., water filtration, product substitution, behavioral modifications), and suggestions for healthcare provider follow-up if results are above the 95th percentile. 5. Focus Groups and Interviews (Qualitative Component): A subset of participants (n≈20) and healthcare providers (n≈10) will engage in virtual focus groups or key informant interviews to provide feedback on report clarity, usability, and communication preferences. These sessions will inform iterative refinements to the report-back materials. 6. Post-Intervention Assessment: Two weeks after receiving their report, participants will complete a follow-up survey assessing: changes in PFAS-specific environmental health literacy, readiness and self-reported behaviors to reduce PFAS exposure, wellness outcomes (stress, sleep, empowerment), and usability, comprehension, and satisfaction with the report-back. Data Collection Instruments: PFAS Environmental Health Literacy Survey (developed and validated for this study), lifestyle and Exposure Audit (expanded to include PFAS-specific questions), and usability and Program Evaluation Questionnaire. Standardized wellness instruments: Perceived Stress Scale (PSS), Behavioral Risk Factor Surveillance System sleep and health modules, and Readiness to change survey based on the Transtheoretical Model of Health Behavior Change. Outcome Measures: Primary Outcomes: 1. Change in PFAS-specific environmental health literacy (pre- vs post-intervention), 2. Change in readiness to reduce PFAS exposure, 3. Change in wellness indicators (stress, sleep, perceived control). Secondary Outcomes: Usability, clarity, and satisfaction with the report-back materials, identification of barriers and facilitators to behavioral change, and qualitative themes on interpretation, comprehension, and behavioral intentions. Data Analysis Plan: Quantitative Analysis: Pre- and post-intervention outcomes will be compared using paired statistical tests (Student's t-test, Wilcoxon signed-rank test for non-normal distributions). Categorical variables will be assessed via chi-square tests. Reliability of PFAS-specific EHL survey will be evaluated using Cronbach's alpha. Secondary exploratory analyses will evaluate correlations between PFAS blood levels, EHL, and self-reported behavior change. Qualitative Analysis: Focus group and interview transcripts will be coded using NVivo software. Two independent coders will identify recurring themes; discrepancies will be resolved via discussion. Thematic analysis will inform report-back refinement, ensuring cultural relevance, clarity, and practicality for rural populations. Ethical Considerations: Participants will be informed of potential risks, including stress associated with receiving exposure results. Personalized counseling and guidance will be provided for individuals with elevated PFAS levels. Ethical principles of autonomy, beneficence, nonmaleficence, and justice will guide all study procedures. Gift card incentives will be provided for survey completion and focus group participation. Significance and Innovation: This study addresses rural health disparities by providing accessible PFAS testing and actionable educational interventions to populations at high risk of exposure. Innovations include: the first direct-to-consumer PFAS mail-in blood test with report-back designed for rural populations and healthcare providers, integration of PFAS biomonitoring with behavioral intervention principles grounded in Self-Regulation Theory, Self-Determination Theory, and the Theory of Planned Behavior, development of the first PFAS-specific environmental health literacy survey, and scalable, low-cost intervention potentially adaptable to other marginalized or underserved populations. Future Directions: Data generated in this Phase I study will inform a Phase II randomized controlled trial to evaluate long-term efficacy, cardiovascular health outcomes, and scalability. The intervention may ultimately be integrated into clinical care, public health programs, and broader population-level PFAS exposure mitigation strategies.
