Human developmental neurotoxicity of methylmercury: impact of variables and risk modifiers

Regul Toxicol Pharmacol. 2008 Jul;51(2):201-14. doi: 10.1016/j.yrtph.2008.01.016. Epub 2008 Feb 13.


Methylmercury (MeHg) is a widespread environmental and food toxicant which has long been known to affect neurodevelopment in both humans and experimental animals. Risk assessment for MeHg is mainly based on human data coming from the massive episodes of poisoning in Japan and Iraq, as well as from large scale epidemiological studies concerning childhood development and neurotoxicity in relation to in utero exposure in various fish eating communities around the world. Despite the extensive literature and research, the threshold dose for MeHg neurotoxic effects is still unclear, in particular when it comes to subtle effects on neurobehaviour. In this article clinical and epidemiological findings concerning the neurodevelopmental toxicity of MeHg are reviewed. Much attention is focussed on the potential impact of factors, such as diet and nutrition, gender, pattern of exposure and co-exposure to other neurotoxic pollutants, which may modulate MeHg toxic effects. These factors, together with the notion that some symptoms may ensue or exacerbate with aging, contribute to the difficulties in the definition of safe levels for developmental exposure.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Child
  • Child, Preschool
  • Environmental Exposure / adverse effects
  • Environmental Pollutants / toxicity*
  • Female
  • Fishes
  • Food Contamination
  • Humans
  • Infant
  • Infant, Newborn
  • Male
  • Mercury Poisoning, Nervous System / epidemiology
  • Mercury Poisoning, Nervous System / physiopathology*
  • Methylmercury Compounds / poisoning*
  • Pregnancy
  • Prenatal Exposure Delayed Effects
  • Risk Assessment
  • Risk Factors


  • Environmental Pollutants
  • Methylmercury Compounds