Children's Health Advance Publication
Prenatal Organochlorine and Methylmercury Exposure and Memory and Learning in School-Age Children in Communities Near the New Bedford Harbor Superfund Site, Massachusetts
This EHP Advance Publication article has been peer-reviewed, revised, and accepted for publication. EHP Advance Publication articles are completely citable using the DOI number assigned to the article. This document will be replaced with the copyedited and formatted version as soon as it is available. Through the DOI number used in the citation, you will be able to access this document at each stage of the publication process.
Citation: Orenstein ST, Thurston SW, Bellinger DC, Schwartz JD, Amarasiriwardena CJ, Altshul LM, Korrick SA. Prenatal Organochlorine and Methylmercury Exposure and Memory and Learning in School-Age Children in Communities Near the New Bedford Harbor Superfund Site, Massachusetts. Environ Health Perspect; http://dx.doi.org/10.1289/ehp.1307804.
Received: 25 October 2013
Accepted: 24 July 2014
Advance Publication: 25 July 2014
Background: Polychlorinated biphenyls (PCBs), organochlorine pesticides, and methylmercury (MeHg) are environmentally persistent with adverse effects on neurodevelopment. However, especially among populations with commonly experienced low levels of exposure, research on neurodevelopmental effects of these toxicants has produced conflicting results.
Objectives: We assessed the association of low-level prenatal exposure to these contaminants with memory and learning.
Methods: 393 children, born between 1993-1998 to mothers residing near a PCB-contaminated harbor in New Bedford, Massachusetts were studied. Cord serum PCB, DDE, and maternal peripartum hair Hg levels were measured to estimate prenatal exposure. Memory and learning were assessed at age 8 (range: 7-11) years using the Wide Range Assessment of Memory and Learning (WRAML), age-standardized to a mean of 100 and standard deviation of 15. Associations with each WRAML index – Visual Memory, Verbal Memory, and Learning – were examined with multivariable linear regression, controlling for potential confounders.
Results: While cord serum PCB levels were low (sum of 4 PCBs, mean: 0.3 ng/g serum; range: 0.01, 4.4), hair Hg levels were typical of the U.S. fish eating population (mean: 0.6 µg/g; range: 0.3, 5.1). In multivariable models, each µg/g increase in hair Hg was associated with, on average, decrements of -2.8 on Visual Memory (95% CI: -5.0, -0.6, p=0.01), -2.2 on Learning (95% CI: -4.6, 0.2, p=0.08), and -1.7 on Verbal Memory (95% CI: -3.9, 0.6, p=0.14). There were no significant adverse associations of PCBs or DDE with WRAML indices.
Conclusions: These results support an adverse relationship between low-level prenatal MeHg exposure and childhood memory and learning, particularly visual memory.
Notice of Intent to RecruitThe National Institute of Environmental Health Sciences will soon announce a search for candidates for the position of Supervisory Technical Editor (Operations Manager) for EHP. The Operations Manager will report directly to the Editor-in-Chief of EHP. To learn more, read the full notice of intent to recruit.
CEHN October 2014 Article of the Month“Maternal Exposure to Criteria Air Pollutants and Congenital Heart Defects in Offspring: Results from the National Birth Defects Prevention Study” (Environ Health Perspect; DOI:10.1289/ehp.1307289) has been selected by the Children’s Environmental Health Network (CEHN) as its October 2014 Article of the Month. These CEHN summaries discuss the potential policy implications of current children’s environmental health research.
Sign Up to Receive E-mail Alerts
Recent Advance Publications
Building a Robust 21st Century Chemical Testing Program at the U.S. Environmental Protection Agency: Recommendations for Strengthening Scientific Engagement
Cadmium and Proliferation in Human Uterine Leiomyoma Cells: Evidence of a Role for EGFR/MAPK Pathways but Not Classical Estrogen Receptor Pathways
Monitoring Indoor Exposure to Organophosphate Flame Retardants: Hand Wipes and House Dust
Use of Satellite Observations for Long-Term Exposure Assessment of Global Concentrations of Fine Particulate Matter
A Targeted Health Risk Assessment Following the Deep Water Horizon Oil Spill: Polycyclic Aromatic Hydrocarbon Exposure in Vietnamese-American Shrimp Consumers