lysis indicates mercury exposure appeared to be associated with inattention and impulsivity/hyperactivity and some outcomes had an apparent threshold with associations at 1 μg/g (microgram/per gram) or greater of mercury. For example, at 1 μg/g or greater, the adjusted risk ratios for mild/markedly atypical inattentive and impulsive/hyperactive behaviors were 1.4 and 1.7 respectively, according to the study results.
There also appeared to be a "protective" (lower risk) association for fish consumption of greater than two servings per week with ADHD-related behaviors, particularly impulsive/hyperactive behaviors (relative risk = 0.4), the study results show.
"In summary, these results suggest that prenatal mercury exposure is associated with a higher risk of ADHD-related behaviors, and fish consumption during pregnancy is associated with a lower risk of these behaviors," the authors conclude. "Although a single estimate combining these beneficial vs. detrimental effects vis-à-vis fish intake is not possible with these data, these findings are consistent with a growing literature showing risk of mercury exposure and benefits of maternal consumption of fish on fetal brain development and are important for informing dietary recommendations for pregnant women."
(Arch Pediatr Adolesc Med. Published online October 8, 2012. doi:10.1001/archpediatrics.2012.1286. Available pre-embargo to the media at http://media.
Editor's Note: This study was supported by grants from the National Institute of Environmental Health Sciences, National Institutes of Health. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
Editorial: Attention-Deficit/Hyperactivity Disorder a Preventable Epidemic?
In an editorial, Bruce P. Lanphear, M.D., M.P.H., of Simon Fraser University, Vancouver, British Columbia, Canada, writes: "The study by Sagiv et al, which tested whether prenatal exposure to methyl mercury was associated with the development of ADHD-related behaviors, is an important and rigorously conducted prospective birth cohort study."
"What are the implications of the Sagiv et al study and other research on environmental contaminants and ADHD? First, we can take some comfort in recent legislation to reduce mercury contamination, at least from domestic sources. Second, these studies should spur our efforts to enhance the collection of data needed to calculate national estimates and trends in ADHD," Lanphear continues.
"Third, it is time to convene a national scientific advisory panel to evaluate environmental influences of ADHD and make recommendations about what can be done to prevent it. Fourth, this study and a flurry of new evidence linking environmental contaminants with ADHD reinforce the urgency of revising the regulatory framework for environmental contaminants and toxicants," Lanphear concludes.
(Arch Pediatr Adolesc Med. Published online October 8, 2012. doi:10.1001/archpediatrics.2012.1900. Available pre-embargo to the media at http://media.
Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
To contact Sharon K. Sagiv, Ph.D., M.P.H., call Tom Langford at 617-534-1605 or email@example.com. To contact editorial author Bruce P. Lanphear, M.D., M.P.H., call 778-782-8650 or email firstname.lastname@example.org.