Mental retardation and prenatal methylmercury toxicity

• Published in: American journal of industrial medicine 2006-03, Vol.49 (3), p.153-158
• Main Authors: Trasande, Leonardo, Schechter, Clyde B., Haynes, Karla A., Landrigan, Philip J.
• Format: Article
• Language: English
• Subjects: 01 COAL, LIGNITE, AND PEAT; Adult and adolescent clinical studies; Biological and medical sciences; BRAIN; Chemical and industrial products toxicology. Toxic occupational diseases; CHILDREN; COAL; Cohort Studies; cord blood; COST; electrical generation facilities; Embryology: invertebrates and vertebrates. Teratology; EMISSION; environmentally attributable fraction; Female; FOSSIL-FUEL POWER PLANTS; Fundamental and applied biological sciences. Psychology; HEALTH HAZARDS; Humans; Infant; Intellectual deficiency; Intellectual Disability - chemically induced; Intellectual Disability - economics; Intellectual Disability - epidemiology; Maternal Exposure - adverse effects; Medical sciences; mental retardation; MERCURY; Metals and various inorganic compounds; METHYLMERCURY; Methylmercury Compounds - blood; Methylmercury Compounds - toxicity; Power Plants; Pregnancy; PRENATAL EXPOSURE; Prenatal Exposure Delayed Effects - epidemiology; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Teratology. Teratogens; TOXICITY; Toxicology; United States - epidemiology; USA
• ISSN: 0271-3586; 1097-0274
• DOI: 10.1002/ajim.20268

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. Am. J. Ind. Med. 49:153–158, 2006. © 2006 Wiley‐Liss, Inc.