Determinants of Medication Storage and Disposal Practices in Brazil: A Cross-Sectional Study with Implications for Environmental Exposure

Background/Objectives: Inappropriate medication storage and disposal are recognized public health concerns and represent a relevant source of environmental exposure to pharmaceutical compounds, with potential implications for ecosystem and human health. Identifying population-level determinants of these behaviors is essential to support targeted interventions and risk mitigation strategies. Methods: A cross-sectional population-based study was conducted using a structured survey administered to Brazilian adults. The questionnaire assessed medication storage practices, disposal behaviors, and prior exposure to guidance on appropriate medication handling. Descriptive statistics were used to characterize the sample, and multivariate logistic regression analysis was performed to identify independent predictors of appropriate disposal practices. Results: A total of 475 participants were included in the analysis. Although awareness of the environmental impact of improper medication disposal was high, inappropriate practices remained prevalent. Multivariate logistic regression identified educational level as the primary independent determinant of appropriate disposal practices (p < 0.001), while no significant associations were observed for age or gender (p > 0.05). Lack of prior guidance was frequent and may represent a relevant population-level exposure influencing unsafe behaviors. Conclusions: The findings highlight a gap between awareness and practice and identify key sociodemographic determinants influencing medication disposal behaviors. From an environmental epidemiology perspective, improper disposal may contribute to the dissemination of pharmaceutical residues in water systems, representing an indirect but widespread exposure pathway. Targeted public health strategies focusing on high-risk groups are needed to promote safe medication handling and reduce environmental and health risks.