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Biomedical subjects

Fernando Ortega

Publications and source records attributed to Fernando Ortega.

21 records · Page 2Linked to original sources

Succimer (meso-2,3-dimercaptosuccinic acid (DMSA)) treatment of Andean children with environmental lead exposure.

The authors studied children in Andean villages contaminated by a lead-glazing cottage industry. Mean blood lead (PbB) level in 35 exposed children, aged 3-14 years, a year before treatment, at the time of initiation of a comprehensive lead education and prevention program, was 53.4 microg/dL. PbB levels immediately before and three weeks after a ten-day regimen of succimer treatment of the 35 children were 43.4 microg/dL and 34.3 microg/dL, respectively, showing a 21% reduction and a significant difference between means (t = 5.09, p = 0.0001). PbB levels of the same children a year before treatment and immediately pre-treatment were also significantly different (t = 10.59, p = 0.0001). Thus, a ten-day course of succimer chelation effectively reduced PbB in children with moderate to severe Pb intoxication, and the education and prevention program, initiated with parents, health care providers, and educators, also contributed significantly to reducing PbB.

Adolescent↗

Mercury levels in urine and hair of children in an Andean gold-mining settlement.

This field study investigated mercury (Hg) levels in urine and hair of Andean children of indigenous Saraguro and Metizo gold miners in the Nambija, Ecuador gold mining settlement. Spot samples of urine and hair samples were collected concurrently from 80 children each. Urine samples were used to determine the inorganic Hg burden, while hair samples were used as an index of methylmercury (MeHg) exposure from consumption of Hg contaminated fish. The mean level of Hg in urine (HgU) was 10.9 microg/L, and the mean level in hair (HgH) was 6.0 microg/g. Regression analysis showed a significant association (r = 0.404, p = 0.0007) between matched HgU and HgH samples. Mean HgU and HgU levels tended to be higher for children aged 6-14 years than for a younger group. The wide range of Hg levels in the urine and hair of Andean children of gold miners may place them at risk for neurodevelopmental and learning disorders.

Adolescent↗

Neurocognitive screening of mercury-exposed children of Andean gold miners.

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 (Hg(B)), urine (Hg(U)), and hair (Hg(H)) samples were 5.1 microg/L (SD: 2.4; range: 1-10 microg/L), 13.3 microg/L (SD: 25.9; range: 1-166 microg/L), and 8.5 microg/g (SD: 22.8; range: 1-135 microg/g), respectively. Of the children in the Nambija area 67-84.9% had abnormal RCPM standard scores (i.e., < or = 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 Hg(B) and Hg(H) 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.

Child↗