Subject: STUDY: The contribution of dental amalgam to urinary mercury excretion in children
Author: Ilena RoseDate: 14 Aug
http://ilenarose.blogspot.com
Health Lover, Ilena Rosenthal
The contribution of dental amalgam to urinary mercury excretion in
children
Environ Health Perspect. 2007 Oct;115(10):1527-31. Woods JS, Martin
MD, Leroux BG, Derouen TA, Leitão JG, Bernardo MF, Luis HS, Simmonds
PL, Kushleika JV, Huang Y.
Department of Environmental and Occupational Health Sciences,
University of Washington, Seattle, Washington, USA.
BACKGROUND: Urinary mercury concentrations are widely used as a
measure of mercury exposure from dental amalgam fillings. No studies
have evaluated the relationship of these measures in a longitudinal
context in children.
OBJECTIVE: We evaluated urinary mercury in children 8-18 years of age
in relation to number of amalgam surfaces and time since placement
over a 7-year course of amalgam treatment.
METHODS: Five hundred seven children, 8-10 years of age at baseline,
participated in a clinical trial to evaluate the neurobehavioral
effects of dental amalgam in children. Subjects were randomized to
either dental amalgam or resin composite treatments. Urinary mercury
and creatinine concentrations were measured at baseline and annually
on all participants.
RESULTS: Treatment groups were comparable in baseline urinary mercury
concentration (~ 1.5 mug/L). Mean urinary mercury concentrations in
the amalgam group increased to a peak of ~ 3.2 mug/L at year 2 and
then declined to baseline levels by year 7 of follow-up.
There was a strong, positive association between urinary mercury and
both number of amalgam surfaces and time since placement. Girls had
significantly higher mean urinary mercury concentrations than boys
throughout the course of amalgam treatment. There were
no differences by race in urinary mercury concentration associated
with amalgam exposure.
CONCLUSIONS: Urinary mercury concentrations are highly correlated with
both number of amalgam fillings and time since placement in children.
Girls excrete significantly higher concentrations of mercury in the
urine than boys with comparable treatment, suggesting possible
sex-related differences in mercury handling and susceptibility to
mercury toxicity.
Mark Thorson
Jan Drew
