New technologies measure ever-lower concentrations of environmental chemicals in human blood, urine, breast milk, and other tissues and in personal spaces such as homes. The earliest exposure measurements for emerging contaminants precede understanding of health effects, sources, and toxicity, since chemicals are put into use without safety testing or product labeling. As a result, exposure studies raise ethical questions about whether and how to report individual results to participants. Medical ethics traditionally favored reporting only clinically significant results, to protect patients from distress. However, community-based participatory research frameworks and activist biomonitoring projects focus on the human research ethics principles of respect for autonomy and the responsibility to maximize benefits, which support study participants’ right-to-know. This symposium will consider ethical and legal issues in reporting individual exposures in academic, government, and activist studies. It will draw on interviews with participants from diverse socioeconomic settings who received results for many endocrine disrupting compounds (EDCs), including compounds recently in the news. Participants dramatically expanded their conceptions of pollution as they learned about consumer-product chemicals in their homes and bodies. Learning personal results motivated action to reduce exposures through both lifestyle changes and policy advocacy.