title: Elevated blood mercury and neuro-otological observations in children of the Ecuadorian gold mines.
abstract: The prevalence of mercury (Hg) intoxication was investigated in 114 Andean Saraguro and non-Saraguro (Mestizo) children living in remote gold-mining settlements in Nambija and Portovelo, Ecuador. Venous blood samples showed a mean total blood mercury (B-Hg) level of 18.2 microg/L (SD 15.5; range 2-89.) for 77 Saraguro and non-Saraguro children in the Nambija settlement, which was significantly higher than that of children in the Portovelo and reference groups. Comparison of groups showed mean B-Hg levels of 26.4 microg/L (range 4-89 microg/L) for 32 indigenous/Saraguro children; 12.3 microg/L (range 2-33 microg/L) for 45 non-Saraguro children; 4.9 microg/L (range 1-10 microg/L) for 37 children in Portovelo; and 2.4 microg/L (range 1-6 microg/L) for a reference group of 15 children. Fisher's post hoc analysis revealed significant differences among groups, except between the Portovelo and the reference groups. Neuro-otological symptoms and abnormalities were observed in Saraguro, non-Saraguro, and Portovelo children. Samples of soil collected at sites near the local school were found to contain Hg levels ranging from 0. 1 to 38 ppm, cadmium (Cd) levels from 0.07 to 0.82 ppm and arsenic (As) levels from < 1 to 3.9 ppm. in conclusion, the children of Nambija, particularly the Saraguro "Amer-Indians," exhibited elevated B-Hg levels from exposure to Hg used in the gold-mining process, and are at risk for neurological impairment. The children of Portovelo who reported neuro-otological symptoms but had low B-Hg levels (<10 microg/L) may be affected by exposure to sodium cyanide, which is used extensively in the local gold-mining operations.
authors.affiliation: Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Cambridge, USA. allen_counter@harvard.edu
authors.forename: S Allen
authors.initials: SA
authors.lastname: Counter
authors.forename: Leo H
authors.initials: LH
authors.lastname: Buchanan
authors.forename: Fernando
authors.initials: F
authors.lastname: Ortega
authors.forename: Göran
authors.initials: G
authors.lastname: Laurell
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004427:Ear Diseases / Q000139:chemically induced* / Q000175:diagnosis / Q000453:epidemiology; D004484:Ecuador / Q000453:epidemiology; D004781:Environmental Exposure; D005260:Female; D006046:Gold; D006801:Humans; D007223:Infant; D008297:Male; D008628:Mercury / Q000032:analysis; D008630:Mercury Poisoning / Q000097:blood*; D008906:Mining; D012989:Soil Pollutants / Q000032:analysis
chemical_list: D012989:Soil Pollutants; D006046:Gold; D008628:Mercury