Increased levels of mercury associated with high fish intakes among children from Vancouver, Canada

Objective

To assess exposure to mercury (Hg) among children in population subgroups whose traditional dietary practices include fish.

Study design

We determined blood Hg, red blood cell phosphatidylethanolamine omega-3 eicosapentaenoic acid as a marker of fish intake, and assessed indexes of childhood behavior in preschool children 1.5 to 5 years of age (n = 228) living in an ethnically diverse neighborhood in Vancouver, British Columbia, Canada.

Results

The median blood Hg was 4.6 nmol/L, range 0-67.9 nmol/L. Twelve (6%) children, all of whom were Chinese, had a blood Hg > 28.9 nmol/L. Blood Hg, total fish intake, and eicosapentaenoic acid were higher among Chinese than Caucasian children; however, higher fish intake did not predict blood Hg. Blood Hg was inversely associated with attentional focusing in children over 3 years of age after adjusting for confounding family variables, iron deficiency anemia, and zinc deficiency. Major sources of fish among Chinese children were imported fish rather than local fish.

Conclusion

Children from population subgroups within populations not considered at risk may be at increased risk of neurotoxicity caused by Hg exposure from fish.

Abbreviations:  CBQ, Child Behavior Questionnaire , ECBQ, Early Child Behavior Questionnaire , EPA, Eicosapentaenoic acid , Hg, Mercury , Me-Hg, Methyl-mercury , RBC PE, Red blood cell phosphatidylethanolamine