From Beliefs to Behaviors: Examining University Students’ Responses to Plastic Pollution Through the Roles of Attitudes and Behavioral Intentions Under Different Barriers

Plastic pollution is a major global environmental challenge requiring changes in individual behaviors alongside technological and policy interventions. This study investigated university students’ beliefs, attitudes, behavioral intentions, and behaviors toward plastic pollution using a modified Theory of Planned Behavior framework. A cross-sectional survey was conducted among 198 undergraduate students from two cohorts enrolled in the Pollution Science course of a Sino-American Environmental Science program. The questionnaire was developed from the literature, validated through expert review and pilot testing, and demonstrated acceptable to excellent internal consistency (Cronbach’s α = 0.701–0.819; overall α = 0.904). Descriptive statistics, Spearman’s rank correlation, multiple linear regression analyses, and mediation analysis were performed. Students demonstrated strong pro-environmental beliefs and positive attitudes, recognizing the environmental and human health risks associated with plastic pollution and microplastics. However, behaviors requiring greater effort or inconvenience, such as bringing reusable takeaway containers and refusing single-use plastics, were practiced less consistently, indicating an attitude–behavior gap. Correlation analysis showed significant positive relationships among beliefs, attitudes, behavioral intentions, and behaviors. Multiple regression revealed that attitudes (β = 0.462, p = 0.001) and behavioral intentions (β = 0.378, p < 0.001) significantly predicted plastic-related behaviors, whereas beliefs did not directly influence behaviors. Mediation analysis further showed a significant indirect effect of beliefs on behaviors through behavioral intentions, whereas the serial pathway through attitudes and behavioral intentions was not significant. No significant differences were observed across gender or year of study. The findings suggest interventions that reduce practical barriers, strengthen students’ behavioral intentions, and improve access to recycling facilities and sustainable alternatives are paramount.