Blood mercury concentrations in CHARGE Study children with and without autism.

Author: Hertz-Picciotto I, Green PG, Delwiche L, Hansen R, Walker C, Pessah IN.

Source: Environ Health Perspect.

Year: 2010

Comment:

While this study found no correlation of mercury levels and autism, it did find greater mercury exposure with gum chewing and teeth grinding in children.

Abstract / Excerpt:

BACKGROUND:

Some authors have reported higher blood mercury (Hg) levels in persons with autism, relative to unaffected controls.

OBJECTIVES:

We compared blood total Hg concentrations in children with autism or autism spectrum disorder (AU/ASD) and typically developing (TD) controls in population-based samples, and determined the role of fish consumption in differences observed.

METHODS:

The Childhood Autism Risk from Genetics and the Environment (CHARGE) Study enrolled children 2-5 years of age. After diagnostic evaluation, we analyzed three groups: AU/ASD, non-AU/ASD with developmental delay (DD), and population-based TD controls. Mothers were interviewed about household, medical, and dietary exposures. Blood Hg was measured by inductively coupled plasma mass spectrometry. Multiple linear regression analysis was conducted (n = 452) to predict blood Hg from diagnostic status controlling for Hg sources.

RESULTS:

Fish consumption strongly predicted total Hg concentration. AU/ASD children ate less fish. After adjustment for fish and other Hg sources, blood Hg levels in AU/ASD children were similar to those of TD children (p = 0.75); this was also true among non-fish eaters (p = 0.73). The direct effect of AU/ASD diagnosis on blood Hg not through the indirect pathway of altered fish consumption was a 12% reduction. DD children had lower blood Hg concentrations in all analyses. Dental amalgams in children with gum-chewing or teeth-grinding habits predicted higher levels.

CONCLUSIONS:

After accounting for dietary and other differences in Hg exposures, total Hg in blood was neither elevated nor reduced in CHARGE Study preschoolers with AU/ASD compared with unaffected controls, and resembled those of nationally representative samples.”

Citation:

Hertz-Picciotto I, Green PG, Delwiche L, Hansen R, Walker C, Pessah IN. Blood mercury concentrations in CHARGE Study children with and without autism. Environ Health Perspect. 2010; 118(1):161-6.