It is important to understand people's risk perception to identify effective pathways for risk communication about per- and polyfluoroalkyl substances (PFAS) because they present emerging environmental health risks. Guided by dual-process theories of information processing, this study focuses on personal relevance as a key variable that influences risk perception, systematic processing, and information seeking intention. Through an experimental survey, we found that participants in the high personal relevance condition (n = 497) were more likely to process information systematically compared to those in the low personal relevance condition (n = 486). Results also revealed that personal relevance influenced systematic processing through risk judgment and emotional response. Message-specific systematic processing was positively associated with information seeking intention. Lastly, trust in government and trust in science had different relationships with systematic processing, demonstrating the importance of distinguishing different types of institutional trust in future research.