Mental retardation and prenatal methylmercury toxicity.
BACKGROUND
Methylmercury (MeHg) is a developmental neurotoxicant; exposure results principally from consumption of seafood contaminated by mercury (Hg). In this analysis, the burden of mental retardation (MR) associated with methylmercury exposure in the 2000 U.S. birth cohort is estimated, and the portion of this burden attributable to mercury (Hg) emissions from coal-fired power plants is identified.


METHODS
The aggregate loss in cognition associated with MeHg exposure in the 2000 U.S. birth cohort was estimated using two previously published dose-response models that relate increases in cord blood Hg concentrations with decrements in IQ. MeHg exposure was assumed not to be correlated with native cognitive ability. Previously published estimates were used to estimate economic costs of MR caused by MeHg.


RESULTS
Downward shifts in IQ resulting from prenatal exposure to MeHg of anthropogenic origin are associated with 1,566 excess cases of MR annually (range: 376-14,293). This represents 3.2% of MR cases in the US (range: 0.8%-29.2%). The MR costs associated with decreases in IQ in these children amount to $2.0 billion/year (range: $0.5-17.9 billion). Hg from American power plants accounts for 231 of the excess MR cases/year (range: 28-2,109), or 0.5% (range: 0.06%-4.3%) of all MR. These cases cost $289 million (range: $35 million-2.6 billion).


CONCLUSIONS
Toxic injury to the fetal brain caused by Hg emitted from coal-fired power plants exacts a significant human and economic toll on American children.
Trasande
Leonardo
L
Department of Community and Preventive Medicine, Center for Children's Health and the Environment, Mt. Sinai School of Medicine, One Gustave K. Levy Place, Box 1043, New York, NY 10029, USA. leo.trasande@mssm.edu
Schechter
Clyde B
CB
Haynes
Karla A
KA
Landrigan
Philip J
PJ
D015331:Cohort Studies; D005260:Female; D006801:Humans; D007223:Infant; D008607:Intellectual Disability / Q000139:chemically induced* / Q000191:economics / Q000453:epidemiology; D018811:Maternal Exposure / Q000009:adverse effects*; D008767:Methylmercury Compounds / Q000097:blood / Q000633:toxicity*; D011210:Power Plants; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000453:epidemiology; D014481:United States / Q000453:epidemiology
D008767:Methylmercury Compounds