Cognitive Deficit in 7-Year-Old Children with Prenatal Exposure to Methylmercury

Delayed brainstem auditory evoked potential latencies in 14-year-old children exposed to methylmercury

“…We previously showed that increased intrauterine MeHg exposures were associated with delayed peak III latencies at age 7 years. 5,18 We hypothesized that these delays would remain at age 14 and that BAEP latencies would also 5 be sensitive to MeHg from adolescent seafood diets.…”

“…7 Concomitant exposure to polychlorinated biphenyls (PCBs) was determined from the concentration in umbilical cords from 438 cohort members. 5 The first follow-up examination was carried out seven years later and included hair-mercury assessment, evoked potentials and pediatric examination. 5,21 At age 14 years, a total of 878 of 1,010 live cohort members (86.9%) were examined.…”

“…5 The first follow-up examination was carried out seven years later and included hair-mercury assessment, evoked potentials and pediatric examination. 5,21 At age 14 years, a total of 878 of 1,010 live cohort members (86.9%) were examined. Hair samples were again obtained, and the proximal 2-cm segment was analyzed by flow-injection cold-vapor atomic absorption spectrometry after digestion of the hair sample in a microwave oven.…”

“…[2][3] Early adverse effects have been characterized by administering neurobehavioral tests to children exposed in utero from maternal seafood diets. [4][5][6] Thus, a National Research Council (NRC) committee 7 recently concluded that intrauterine MeHg exposure was the most critical and emphasized the findings from a prospective birth cohort study carried out in the Faroe Islands. 5 The damage to the developing nervous system is thought to be potentially irreversible.…”

“…[4][5][6] Thus, a National Research Council (NRC) committee 7 recently concluded that intrauterine MeHg exposure was the most critical and emphasized the findings from a prospective birth cohort study carried out in the Faroe Islands. 5 The damage to the developing nervous system is thought to be potentially irreversible. 7 The possibility also exists that exposure during postnatal development may induce brain lesions; clinical 2,8 and experimental 9 information suggests that such effects would tend to be more focal and particularly involve the sensory cortex and the granular layer of the cerebellum.…”