Inhalational mercury toxicity from artisanal gold extraction reported to the Oregon poison center, 2002–2015

Context: Mercury exposure has been described among small-scale gold mining communities in developing countries, but reports of inhalational mercury toxicity among home gold extractors in the US remain uncommon. Objective: We sought to identify inhalational mercury exposures and toxicity among artisanal gold extractors. Methods: This is an observational case series of a single Poison Center database from 2002–2015. We review all cases of “mercury” or “mercury inhalation” exposures, with detailed description of a recent representative case. Results: Nine cases were reported, with patients’ ages ranging 32–81 years. Eight (89%) patients were male. Seven of eight (88%) patients with acute exposures reported pulmonary symptoms consistent with mercury vapor inhalation such as dyspnea and cough; two (29%) patients had severe toxicity requiring intubation. Four of six (67%) patients had markedly elevated whole blood mercury concentrations up to 346 mcg/L; each received a different chelation regimen. Four (44%) patients used methamphetamines at the time of their exposure. The case report describes a patient with elevated mercury concentrations who required intubation for hypoxic respiratory failure. He received chelation therapy based on chelator availability, with decreasing 24-hour urine mercury concentrations. The house where he was exposed remains uninhabitable from elevated ambient mercury vapor concentrations. Conclusion: Artisanal gold extraction may be associated with inhalational mercury toxicity, including elevated blood mercury concentrations and acute hypoxic lung injury requiring intubation.