title: Signs and symptoms of mercury-exposed gold miners.
abstract: OBJECTIVE
  Gold miners use mercury to extract gold from ore adding liquid mercury to the milled gold-containing ore. This results in a mercury-gold compound, called amalgam. Miners smelt this amalgam to obtain gold, vaporizing it and finally inhaling the toxic mercury fumes. The objective was to merge and analyze data from different projects, to identify typical signs and symptoms of chronic inorganic mercury exposure.
  
  
  METHODS
  Miners and community members from various artisanal small-scale gold mining areas had been examined (Philippines, Mongolia, Tanzania, Zimbabwe, Indonesia). Data of several health assessments were pooled. Urine, blood and hair samples were analyzed for mercury (N = 1252). Questionnaires, standardized medical examinations and neuropsychological tests were used. Participants were grouped into: Controls (N = 209), living in an exposed area (N = 408), working with mercury as panners (N = 181), working with mercury as amalgam burners (N = 454). Chi2test, linear trend test, Mann-Whitney test, Kruskal-Wallis test, correlation coefficient, Spearman's rho, and analysis of variance tests were used. An algorithm was used to define participants with chronic mercury intoxication.
  
  
  RESULTS
  Mean mercury concentrations in all exposed subgroups were elevated and above threshold limits, with amalgam burners showing highest levels. Typical symptoms of chronic metallic mercury intoxication were tremor, ataxia, coordination problems, excessive salivation and metallic taste. Participants from the exposed groups showed poorer results in different neuropsychological tests in comparison to the control group. Fifty-four percent of the high-exposed group (amalgam burners) were diagnosed as being mercury-intoxicated, compared to 0% within the control group (Chi2p < 0.001).
  
  
  CONCLUSIONS
  Chronic mercury intoxication, with tremor, ataxia and other neurological symptoms together with a raised body burden of mercury was clinically diagnosed in exposed people in artisanal small-scale mining areas. The mercury exposure needs to be urgently reduced. Health care systems need to be prepared for this emerging problem of chronic mercury intoxication among exposed people. Int J Occup Med Environ Health 2017;30(2):249-269.
authors.affiliation: University Hospital Munich, Munich, Germany (Institute and Outpatient Clinic for Occupational, Social and Environmental Medicine, WHO Collaborating Centre for Occupational Health). stephan.boeseoreilly@med.uni-muenchen.de.
authors.forename: Stephan
authors.initials: S
authors.lastname: Bose-O'Reilly
authors.affiliation: United Nations Industrial Development Organization (UNIDO), Vienna, Austria (Vienna International Centre). L.Bernaudat@unido.org.
authors.forename: Ludovic
authors.initials: L
authors.lastname: Bernaudat
authors.affiliation: The Health and Life Sciences University (UMIT), Hall in Tirol, Austria (Institute of Public Health, Medical Decision Making and Health Technology Assessment Department of Public Health, Health Services Research and Health Technology Assessment). uwe.siebert@umit.at.
authors.forename: Uwe
authors.initials: U
authors.lastname: Siebert
authors.affiliation: University of Munich, Munich, Germany (Department of Forensic Toxicology, Institute of Forensic Medicine). Gabriele.Roider@med.uni-muenchen.de.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Roider
authors.affiliation: University Hospital Munich, Munich, Germany (Institute and Outpatient Clinic for Occupational, Social and Environmental Medicine, WHO Collaborating Centre for Occupational Health). dennis.nowak@med.uni-muenchen.de.
authors.forename: Dennis
authors.initials: D
authors.lastname: Nowak
authors.affiliation: University of Munich, Munich, Germany (Department of Forensic Toxicology, Institute of Forensic Medicine). drasch@allacher-apotheke.de.
authors.forename: Gustav
authors.initials: G
authors.lastname: Drasch
mesh_terms: D001259:Ataxia / Q000139:chemically induced; D001822:Body Burden; D005260:Female; D006046:Gold; D006197:Hair / Q000737:chemistry; D006801:Humans; D008297:Male; D008628:Mercury / Q000097:blood* / Q000652:urine*; D020262:Mercury Poisoning, Nervous System / Q000453:epidemiology*; D008669:Metallurgy; D000067572:Miners; D009483:Neuropsychological Tests; D016273:Occupational Exposure; D014202:Tremor / Q000139:chemically induced
chemical_list: D006046:Gold; D008628:Mercury
keywords: artisanal small-scale gold mining; chronic mercury intoxication; clinical symptoms; elemental mercury; mercury; neurological symptoms