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Document ID (ISN)105493
CIS number 06-908
ISSN - Serial title 1077-3525 - International Journal of Occupational and Environmental Health
Year 2006
Convention or series no.
Author(s) Counter S.A., Buchanan L.H., Ortega F.
Title Neurocognitive screening of mercury-exposed children of Andean gold miners
Bibliographic information July-Sep. 2006, Vol.12, No.3, p.209-214. Illus. 33 ref.
Internet access http://www.ijoeh.com/pfds/IJOEH_1203_Counter.pdf [in English]
Abstract Performance on Raven's Coloured Progressive Matrices (RCPM) test of visual-spatial reasoning was used to evaluate the effects of mercury (Hg) exposure on 73 Andean children aged 5 to 11 years (mean: 8.4) living in the Nambija and Portovelo gold mining areas of Ecuador, where Hg is widely used in amalgamation. Mean levels of Hg found in blood (HgB), urine (HgU), and hair (HgH) samples were 5.1 µg/L (SD: 2.4; range: 1-10 µg/L), 13.3 µg/L (SD: 25.9; range: 1-166 µg/L), and 8.5 µg/g (SD: 22.8; range: 1-135 µg/g), respectively. Of the children in the Nambija area 67-84.9% had abnormal RCPM standard scores (i.e.≤ 25%tile), depending on the test norm used in the data analysis. Higher standard scores for Peruvian (t=4.77; p=<0.0001) and Puerto Rican (t=4.51; p=<0.0001) norms than for U.S. norms suggested a linguistic influence. No difference was found between Peruvian and Puerto Rican norms (t=0.832; p=<0.408), which showed a significant positive correlation (r=0.915, p=<0.0001). Children with abnormal HgB and HgH levels had significantly lower scores on the RCPM subtest B than did children with nontoxic Hg levels (t=-2.16; p=<0.034). These results suggest that a substantial number of Hg-exposed children in the Nambija study area have neurocognitive deficits in visual-spatial reasoning. [Abstract supplied by the journal]
Descriptors (primary) neurotoxic effects; gold mining; mercury; children
Descriptors (secondary) Ecuador; exposure evaluation; cognitive performance
Document type D - Periodical articles
Country / State or ProvinceEcuador; USA
Subject(s) Toxic and dangerous substances
Broad subject area(s) Chemical safety
Browse category(ies) Diseases of the nervous system
Mining and quarrying
Mercury and compounds
Inorganic substances