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Hair Mercury Levels, Fish Consumption and Cognitive Development in Preschool Children from Southern Spain

Freire, Carmen*; Ramos, Rosa*; Lopez-Espinosa, Maria-Jose*†; Díez, Sergi; Vioque, Jesús§; Ballester, Ferrán; Fernández, Marieta*

doi: 10.1097/01.ede.0000362461.01515.ce
Abstracts: ISEE 21st Annual Conference, Dublin, Ireland, August 25–29, 2009: Symposium Abstracts

*Laboratory of Medical Investigations, San Cecilio University Hospital, University of Granada, CIBER de Epidemiología y Salud Pública (CIBERESP), Granada, Spain; †Center for Research on Public Health (CSISP), Conselleria de Sanitat, Generalitat Valenciana, CIBER de Epidemiología y Salud Pública (CIBERESP), Valencia, Spain; ‡Environmental Geology Department, ICTJA-CSIC; Environmental Chemistry Department, IIQAB-CSIC, Barcelona, Spain; and §Department of Public Health, Universidad Miguel Hernandez (UMH); CIBER de Epidemiología y Salud Pública (CIBERESP), Alicante, Spain.


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Background and Objective:

The main source of human exposure to mercury is the consumption of fish contaminated with methylmercury, which may adversely affect early neurodevelopment. This study assessed mercury levels in hair of preschoolers in Spain, where fish consumption is elevated, with the aim of investigating the influence of their fish intake and other factors on mercury exposure and evaluating their association with cognitive development.

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A population-based birth cohort from Southern Spain was studied at the age of 4 yrs. Total mercury (T-Hg) levels were determined in children's hair, and daily fish intake was assessed by a food frequency questionnaire. The McCarthy Scales of Children's Abilities (MSCA) were used to assess children's motor and cognitive abilities. Complete data were gathered on 72 children, and multivariate analyses were performed to evaluate the influence of mercury exposure and fish intake on MSCA outcomes.

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Mean concentration of T-Hg in hair was 0.96 μg/g (95% confidence interval = 0.76; 1.20 μg/g). T-Hg levels were associated with higher frequency of oily fish consumption, place of residence, maternal age and passive smoking. After adjustment for fish intake, T-Hg levels >1 μg/g were associated with decrements in the general cognitive (−6.6 points), memory (−8.4 points) and verbal (−7.5 points) MSCA scores.

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Higher mercury exposure in children from this Mediterranean area was associated with cognitive development delay. Studies on the putative benefits of fish intake during early development should consider mercury exposure from different fish species.

© 2009 Lippincott Williams & Wilkins, Inc.