Biomonitoring of Occupational Exposure to Mercury Among Dental Health Workers in LMICs: A Systematic Review

Abstract

Mercury exposure remains a significant occupational hazard for dental health workers, especially in low- and middle-income countries (LMICs), due to the continued use of dental amalgam. This systematic review synthesizes the existing evidence on mercury exposure in dental professionals, focusing on biomonitoring data and associated health outcomes in LMICs. In December 2024, a comprehensive literature search was conducted across three electronic databases, PubMed, Scopus and Web of Science to identify primary research studies published from January 2014 onwards. Studies assessing occupational mercury exposure through biomonitoring in dental health workers were included. Nine studies, encompassing 524 dental professionals, met the inclusion criteria. Mercury biomonitoring was conducted using blood (n = 3), urine (n = 7) and hair samples (n = 2). Most studies reported elevated mercury levels in dental workers compared to control groups. Environmental monitoring data further indicated that mercury vapor concentrations in dental clinics may exceed recommended safety thresholds. However, current evidence regarding potential health effects associated with occupational exposure to mercury is inconclusive due to methodological limitations. Mercury remains an occupational hazard for dental health workers in LMICs. As dental amalgam continues to be used in resource-limited settings, implementing biomonitoring programs could enable early detection of mercury-related health issues, protecting workers' health until global mercury phase-down goals are achieved.