<![CDATA[Background: Coastal communities face high vulnerability to microplastic exposure due to widespread environmental contamination and limited risk awareness, prompting this study to develop, validate, and evaluate a behavior-change–oriented educational module to reduce such exposure. Methods: This study applied a Research and Development (R&D) approach comprising the stages Analyze, Design, Develop, Implement, and Evaluate. The analysis phase included a behavioral survey (n = 111) and focus group discussions with key stakeholders. The module underwent expert validation and was piloted among 29 coastal residents, with behavior measured using pre–post instruments. Quantitative data were analyzed using paired t-tests or Wilcoxon tests, while qualitative data were thematically analyzed to assess feasibility and acceptability. Results: Survey and FGD findings indicated low knowledge, incorrect risk perceptions, and environmentally unsafe practices, exacerbated by structural constraints such as limited waste services. The validated module demonstrated high content validity (S-CVI/Ave = 93%; S-CVI/UA = 86%). Pilot implementation showed a significant improvement in knowledge (Z = −4.372; p < 0.001) and attitudes (t = −2.559; p = 0.016). Qualitative evaluations confirmed that the module was easy to use, contextually relevant, and operationally feasible for community-based health education. These findings align with evidence that structured, visual, and participatory learning strategies effectively promote environmental health behavior change. Conclusion: The behavior-change educational module effectively improved microplastic-related behaviors among coastal communities and is feasible for broader community-empowerment implementation provided that sustained cross-sectoral support is ensured.]]>
