Network Analysis and Umbrella Review of the Health Effects of Metals: Part 2, Mercury

Background: Mercury (Hg) is a persistent environmental toxicant with well-documented neurotoxic and cardiometabolic effects.Despite extensive research, inconsistencies remain regarding the understanding of its health risks at low exposure levels and in different populations.Objectives: This umbrella review aimed to integrate current evidence on mercury exposure and its health impacts through a systematic evaluation of published reviews and meta-analyses.Methods: Following PRISMA 2020 guidelines, systematic reviews and meta-analyses published before April 2024 were identified through PubMed and Embase.Studies assessing mercury exposure in relation to human health outcomes were included, and data were synthesized to evaluate consistency and strength of associations.Results: A total of 12 systematic reviews and meta-analyses were included.The findings indicated significant associations between low-level mercury exposure and neurological, cardiovascular, and developmental disorders, particularly among vulnerable groups.However, heterogeneity in exposure metrics and confounding control limited comparability across studies.Conclusions: This umbrella review highlights mercury's continued relevance as a global health concern, emphasizing the need for standardized exposure assessment and improved evaluation of low-level effects to inform public health policies and risk-reduction strategies.