Association of Blood Heavy Metal Concentrations with Hearing Loss: A Bibliometric Analysis

A BSTRACT Heavy metals are persistent environmental toxicants with established neurotoxic effects, and growing evidence suggests that blood concentrations of metals such as lead, mercury, cadmium, and arsenic may be associated with auditory dysfunction. However, the global research structure and thematic development of this field have not been systematically examined. This bibliometric study quantitatively mapped the intellectual structure, publication dynamics, citation impact, and thematic evolution of research on the association between blood heavy metal concentrations and hearing loss. Publications indexed in Scopus and Web of Science from 1977 to 2026 were analyzed. English-language original articles and reviews investigating blood heavy metal exposure and hearing outcomes were included. Records were merged and deduplicated using the bibliometrix package in RStudio, and performance indicators and science mapping techniques were applied to evaluate publication trends, citation impact, collaboration networks, and thematic development. A total of 200 publications were included. Research output increased markedly after 2010, with peak productivity observed between 2020 and 2026. Lead was the most frequently investigated metal, particularly in pediatric and occupational populations. The United States and China were the leading contributors, with the United States serving as the principal collaboration hub. Lead exposure and pediatric hearing loss emerged as core research themes, with growing interest in predictive modeling and mechanistic biomarkers. Overall, research on blood heavy metal exposure and hearing loss has expanded substantially but remains geographically concentrated and predominantly focused on lead. Broader investigation of other metals and stronger international collaboration are needed to advance environmental auditory health research.