Abstract
Methylmercury poisoning may cause constriction of visual fields and deafness, especially if exposure occurs prenatally. However, the risks associated with exposure from contaminated seafood is unclear. We examined 149 children attending first grade in a Madeiran fishing community. As maternal dietary habits were relatively unchanged, current maternal hair concentrations were used as indicator of the child's prenatal exposure to methylmercury (geometric average, 9.64 μg/g [48.2 nmol/g]). After adjustment for age and sex, the mean (±SD) latency of peak III of the brainstem auditory evoked potentials at 40 Hz was increased by 0.128 ± 0.047 ms when maternal hair-mercury concentrations exceeded 10 μg/g (50 nmol/g) (p for association, 0.002), and the increase of the N145 pattern-reversal visual evoked potential latency at 15 minutes of arc was 3.16 ± 1.57 ms (p for association, 0.002). No such relationships were seen with the child's own hair-mercury concentration, and other clinical examinations revealed no mercury-associated deficits. Neurophysiological evidence of adverse effects on brain function are relatively independent of confounders, and should be considered in the risk assessment of this seafood pollutant.
Original language | English |
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Pages (from-to) | 343-348 |
Number of pages | 6 |
Journal | Neurotoxicology and Teratology |
Volume | 21 |
Issue number | 4 |
Early online date | 14 Jul 1999 |
DOIs | |
Publication status | Published - Jul 1999 |
Keywords
- Environmental pollution
- Evoked potentials
- Food contamination
- Methylmercury compounds
- Prenatal exposure delayed effects