Global imbalances in tropical Cesium-137 bioaccumulation research: A PRISMA-guided bibliometric assessment of geographic and methodological disparities

Cesium-137 (¹³⁷Cs) poses heightened radiological risks in tropical and subtropical ecosystems due to environmental conditions that enhance its mobility. Yet, a diagnostic bibliometric analysis of 38 empirical studies (2005–2024) reveals that knowledge production is shaped by epistemic asymmetry rather than ecological need. We find a reactive research agenda, thematic overemphasis on soil systems, and a stark productivity–impact decoupling: Brazil and India produce 60 % of studies but receive only 22 % of citations, reflecting systemic inequities in visibility and authority. High-risk regions including Malaysia and Central Africa remain absent from authorship and discourse. These patterns constrain the validity of region-specific risk assessments. We propose three evidence-based shifts: (1) IAEA-coordinated tropical-specific radioecological protocols; (2) targeted funding for underrepresented ecosystems; and (3) equitable international collaboration through co-leadership and open data sharing. All data are publicly archived (DOI: 10.5281/zenodo.17529451).