A spatio-temporal systematic evidence map of exposure to bisphenols and their alternatives: Social and environmental justice

BACKGROUND: Bisphenol A (BPA) and a growing number of its structural analogues and functional alternatives are widely used in consumer plastic products and therefore have high exposure potential. Social and environmental justice (SEJ) issues arise when exposure or health risks are unevenly distributed across populations. However, no global synthesis of their exposure levels exists. OBJECTIVE: To systematically map concentrations of bisphenols and alternatives in humans, visualising patterns by country, population characteristics, and over time, and identifying research gaps relevant to SEJ. DATA SOURCES: MEDLINE®, Embase and Web of Science databases and 16 grey literature sources. STUDY ELIGIBILITY CRITERIA: Primary studies that reported concentrations of at least one of 90 relevant chemicals in human bio-samples. Study quality was not evaluated. RESULTS: The SEJ Bisphenol Map (https://osf.io/zhe69/) includes 1413 primary research articles. Studies were disproportionately concentrated in high-income countries, with limited evidence from low-income countries and Small Island Developing States. BPA was the most frequently measured chemical, while data on BPA analogues and non-bisphenol alternatives were sparse. Children under two years old were commonly studied, but few studies examined elderly populations and workers or residents near plastics production and waste facilities. Sociodemographic variables, including socio-economic status and ethnicity, were inconsistently reported and no study explicitly considered sexual and gender minority populations. CONCLUSIONS: This first systematic evidence map of bisphenols and alternatives exposure highlights major gaps in geographic coverage, chemical scope, and sociodemographic reporting. Geographically diverse studies and explicit equity considerations are essential to strengthen the evidence base and guide equitable interventions. SYSTEMATIC MAP REGISTRATION NUMBER: The protocol was registered prospectively with Open Science Framework (OSF) on the 6th of November 2023 (https://doi.org/10.17605/OSF.IO/MNWTD; https://osf.io/mnwtd).