Threat and Efficacy in Persuasive Messages About PFAS in Public Drinking Water

Effective risk communication about per-and-polyfluoroalkyl substances (PFAS) is essential due to health risks and low public awareness. Guided by the Extended Parallel Process Model (EPPM) and the Transtheoretical Model (Stages of Change), this study examined how risk-based messages, which include threat and efficacy, influence behavioral intention, advice outcomes, and perceived importance. An experimental survey manipulating threat (high/low) and efficacy (high/low) on 419 municipal water users in Wisconsin found that intentions to reduce PFAS exposure were higher in high-efficacy than low-efficacy messages, especially among those in later stages of change. Perceived importance was higher in the high health-threat condition than in the low-threat condition. Findings emphasize the need to include strong efficacy cues in risk messaging and tailor public health messages to individuals’ readiness for behavior change.