Reviews
June 2011 Newsletter
Lily Xiao Bin Cao-Cao RN*1, Irvica Galla RN*1, Perry Sheffield MD MPH2, Margaret Rafferty DNP MPH1 (*share first authorship)
1 New York City College of Technology, The City University of New York
2Department of Preventive Medicine, Mount Sinai School of Medicine, New York, NY
From Environ Health Perspect. 2011 Sep 1. [Epub ahead of print]
Associations of Early Childhood Manganese and Lead Co-exposure with Neurodevelopment.
Claus Henn, B, Schnaas, L., Ettinger, AS, Schwartz J, Lamadrid-Figuero H, Hernandex-Avila M, Amariasiriwardena C, Hu H, Bellinger DC, Wright RO, Tellez-Rojo MM. Harvard School of Public Health
In groundbreaking research, U.S. and Mexican scientists assessed the synergistic effect of manganese and lead, two known neurotoxins. Little is known about the role that combined chemical exposure plays in the cognitive and motor developmental delays in young children. The purpose of the study was to investigate whether manganese-lead co-exposure was associated with greater neurodevelopmental deficiencies than either of the metals taken separately. Four hundred fifty-five Mexican children who were part of a larger study that followed children from birth through 36 months of age were included in this research. Neurodevelopment was tested at six-month intervals (12, 18, 24, 30 and 36 months) using the Bayley Scales of Infant Development-II. Archived blood samples collected at 12 and 24 months were analyzed in the Harvard Laboratories. Potential confounders, such as birth weight and maternal /parental sociodemographic status, were controlled to prevent bias. The study found that children with higher manganese levels at 12 months who also had elevations of lead, subsequently performed worse on the Bayley Scales. This pattern was not evident at 24 months. Joint exposure to manganese and lead were associated with greater deficits on the Bayley Scales than exposure to either metal alone.
The research raises important questions about the vulnerability of the developing brain to the combined effect of toxic metals with profound implications for public health. Given the millions of children worldwide with elevated lead levels, does co-exposure to manganese cause more vulnerability to cognitive and motor deficits? The finding that twelve months was a sensitive developmental window for the interaction of these two metals requires more investigation in order to inform practice decisions.
Submitted by
Perry Sheffield
perry.sheffield@mssm.edu
Previous Newsletter Articles
- April 2011 Article
- February 2011 Article
- December 2010 Article
- October 2010 Article
- August 2010 Article
- June 2010 Article
- April 2010 Article
- February 2010 Article
