Abstract
Plastic pollution poses severe threats to ecosystems, human health, and economies as plastics fragment into macro- and microplastics that accumulate across marine and terrestrial environments. Conventional monitoring is constrained by scale, cost, and resources, particularly in under-resourced regions, whereas citizen science provides an inclusive, community-driven alternative for data collection, analysis, and remediation to support evidence-based policy. This systematic review advances the field through three novel contributions: a refined participatory typology that explicitly prioritizes co-creative models for equitable engagement in the Global South; the first comprehensive synthesis of direct citizen involvement in plastic bioremediation, including community microbial isolation, household biodegradation trials, and real-world testing of biodegradable materials; and a new conceptual framework positioning citizen science as the central nexus linking upstream prevention, technological innovation, bioremediation, and global governance. Findings highlight large-scale geotagged datasets, behavioral change, and policy influence, while persistent challenges include data standardization, digital exclusion, and Global North bias. We therefore advocate institutional mainstreaming through dedicated policy offices, decolonial integration of indigenous knowledge, and hybrid citizen–lab validation pipelines, especially in underrepresented regions such as Africa, establishing citizen science as a transformative mechanism for participatory and equitable responses to escalating plastic pollution.