Mental retardation and prenatal methylmercury toxicity

Area of Science:

• Environmental Health
• Neuroscience
• Public Health

Background:

• Methylmercury (MeHg) is a potent neurotoxicant impacting fetal development.
• Seafood consumption is the primary source of human exposure to mercury (Hg).
• This study quantifies the burden of mental retardation (MR) linked to MeHg in the US birth cohort.

Purpose of the Study:

• Estimate the prevalence of MR associated with MeHg exposure in the 2000 US birth cohort.
• Identify the contribution of mercury (Hg) emissions from coal-fired power plants to this burden.
• Assess the economic costs of MeHg-induced MR.

Main Methods:

• Utilized two established dose-response models linking cord blood Hg levels to IQ decrements.
• Assumed no correlation between MeHg exposure and inherent cognitive ability.
• Incorporated prior estimates for calculating the economic impact of MR.

Main Results:

• Prenatal MeHg exposure is linked to 1,566 excess annual MR cases (3.2% of total), costing $2.0 billion.
• Coal power plant Hg emissions account for 231 excess MR cases annually (0.5%), with costs of $289 million.
• Estimated ranges indicate significant variability in these figures.

Conclusions:

• Mercury (Hg) emissions from coal-fired power plants impose a substantial human and economic cost on American children.
• Toxic injury to the fetal brain from Hg pollution has significant public health implications.
• Addressing Hg emissions is crucial for protecting child neurodevelopment.