Scalp hair and urine mercury content of children in the Northeast United States: the New England Children's Amalgam Trial.
Children may be at particular risk from toxic effects of mercury (Hg). Previous studies of hair (organic) and urine (inorganic) Hg levels in US children were unable to assess Hg levels while accounting for exposure to amalgam dental restorations. This analysis describes, over a 5-year period, levels and correlates/predictors of scalp hair (H-Hg) and urinary (U-Hg) mercury in 534 New England Children's Amalgam Trial (NECAT) participants, aged 6-10 years and without exposure to dental amalgam at baseline.


RESULTS
Mean H-Hg levels were between 0.3 and 0.4 microg/g over 5 years. 17-29% of children had H-Hg levels > or = 0.5 microg/g, and 5.0 to 8.5% of children had levels > or = 1 microg/g, in any given study year. In adjusted models, fish consumption frequency was the most robust predictor of high H-Hg. U-Hg mean levels were between 0.7 and 0.9 microg/g creatinine over two years. The percentage of those with U-Hg > or 2.3 microg/g creatinine ranged from 4% to 6%. Number of amalgam restorations had a significant dose-response relationship with U-Hg level. Daily gum chewing in the presence of amalgam was associated with high U-Hg.
Dunn
Julie E
JE
New England Research Institutes, 9 Galen St., Watertown, MA, USA. jdunn@nesa.edu
Trachtenberg
Felicia L
FL
Barregard
Lars
L
Bellinger
David
D
McKinlay
Sonja
S
D000818:Animals; D002638:Chewing Gum / Q000706:statistics & numerical data; D002648:Child; D003723:Dental Amalgam / Q000378:metabolism*; D004032:Diet / Q000706:statistics & numerical data; D005260:Female; D005399:Fishes; D006197:Hair / Q000737:chemistry*; D006801:Humans; D008297:Male; D008628:Mercury / Q000652:urine*
D002638:Chewing Gum; D003723:Dental Amalgam; D008628:Mercury