ABSTRACT:
Lead exposure remains a major and preventable global health problem, yet its burden among Indigenous Peoples has not been comprehensively assessed. This systematic review synthesizes published evidence on blood lead levels (BLLs) among Indigenous populations worldwide and examines how structural inequities shape both exposure patterns and the production of knowledge. Following PRISMA 2020 guidelines, we identified 65 studies published between 1967 and 2024, encompassing 121 Indigenous Peoples living in 21 countries from all World Health Organization regions. Across studies, reported BLLs were consistently above current international reference values in both children and adults. In studies including non-Indigenous comparison groups, Indigenous participants most often exhibited higher BLLs, indicating persistent disparities in exposure. Despite this consistent signal of elevated exposure, the evidence base is characterized by substantial gaps and limitations. Indigenous territories in Africa and Asia were markedly underrepresented, while research was heavily concentrated in a small number of high-income countries. Most studies relied on cross-sectional designs, convenience sampling, and heterogeneous reporting practices, limiting comparability across settings. Exposure source attribution was predominantly inferential, based on questionnaires or environmental co-occurrence, and only four studies employed isotopic methods to trace contamination pathways directly. Taken together, the literature suggests that elevated lead exposure among Indigenous Peoples is not an isolated or sporadic phenomenon, but a recurring pattern that remains weakly integrated into public health surveillance. Strengthening standardized biomonitoring, expanding coverage in underrepresented regions, and linking environmental and human exposure data are necessary steps to translate existing knowledge into effective prevention and more equitable global health responses. Finally, it is also fundamental that Indigenous communities are not positioned as study subjects but as active participants in research design, interpretation, or priority setting, incorporating Indigenous perspectives on exposure, risk, and intervention.