Seafood ChoiCeS

Seafood Choices: Balancing Benefits and Risks
http://www.nap.edu/catalog/11762.html
hEALTh RISKS ASSOCIATED WITh SEAFOOD CONSUMPTION
1022 consecutive singleton births from 1986–1987.The objective of this study
was to investigate possible neurobehavioral effects of prenatal exposure to
neurotoxicants, such as methylmercury. The Faroese are high consumers of
seafood, including pilot whale, which exposes them to high levels of methylmercury.
The study team analyzed maternal hair mercury concentrations and
cord blood mercury concentrations at birth and conducted neurobehavioral
examinations on 917 of the children just before school entry (about 7 years of
age) and at 14 years of age. The detailed examinations, which lasted about
5 hours for each child, took place mostly in the National Hospital in Torshavn,
the capital of the Faroes Island. The examination included finger tapping;
hand-eye coordination; reaction time on a continuous performance test;
Wechsler Intelligence Scale for Children—Revised Digit Span, Similarities,
and Block Design; Bender Visual Motor Gestalt Test; Boston Naming Test;
and California Verbal Learning Test. The parent accompanying the child (usually
the mother) was also asked to fill out a self-administered questionnaire
on the child’s past medical history, current health status, and social factors
(Grandjean, 1997).
New Zealand Study
The New Zealand Study involved the screening of 11,000 children born in
1978, over 900 of whose mothers consumed fish more than four times per
week during pregnancy. As with the other cohorts, the objective of this study
was to investigate the association between prenatal mercury exposure and
subsequent development during childhood (Crump, 1998). Maternal hair
samples were collected at birth to assess mercury exposure during pregnancy.
At 4 years of age, the Denver Developmental Screening Test and a set of
neurological screening tests were completed on 74 children, 38 with “high”
maternal hair mercury levels (> 6µg/g) and 36 with “low” maternal hair mercury
levels, matched on maternal demographic characteristics, age, hospital where
the birth took place, and date of birth. Maternal interviews about the ages
at which the child achieved developmental milestones were also conducted
(Kjellstrom et al., 1986). At 6 years of age, 238 children were evaluated. A
child with a high maternal hair mercury was matched with three children with
low hair mercury levels, but similar in gender, maternal ethnic group, age,
smoking habits, location of residence, and number of years living in New
Zealand (Kjellstrom et al., 1989). The tests administered included the Test of
Oral Language Development, the Weschlar Intelligence Scale for Children-
Revised, and the McCarthy Scales of Children’s Abilities.
Copyright © National Academy of Sciences. All rights reserved.