The developmental neurotoxicity of arsenic: cognitive and behavioral consequences of early life exposure

Ann Glob Health. Jul-Aug 2014;80(4):303-14. doi: 10.1016/j.aogh.2014.09.005. Epub 2014 Nov 25.

Abstract

Background: More than 200 million people worldwide are chronically exposed to arsenic. Arsenic is a known human carcinogen, and its carcinogenic and systemic toxicity have been extensively studied. By contrast, the developmental neurotoxicity of arsenic has been less well described. The aim of this review was to provide a comprehensive review of the developmental neurotoxicity of arsenic.

Methods: We reviewed the published epidemiological and toxicological literature on the developmental neurotoxicity of arsenic.

Results: Arsenic is able to gain access to the developing brain and cause neurotoxic effects. Animal models link prenatal and early postnatal exposure to reduction in brain weight, reductions in numbers of glia and neurons, and alterations in neurotransmitter systems. Animal and in vitro studies both suggest that oxidative stress may be a mechanism of arsenic neurotoxicity. Fifteen epidemiological studies indicate that early life exposure is associated with deficits in intelligence and memory. These effects may occur at levels of exposure below current safety guidelines, and some neurocognitive consequences may become manifest only later in life. Sex, concomitant exposures, and timing of exposure appear to modify the developmental neurotoxicity of arsenic. Four epidemiological studies failed to show behavioral outcomes of arsenic exposure.

Conclusions: The published literature indicates that arsenic is a human developmental neurotoxicant. Ongoing and future prospective birth cohort studies will allow more precise definition of the developmental consequences of arsenic exposure in early life.

Keywords: arsenic; behavioral effects; children’s environmental health; cognition; developmental neurotoxicity; developmental origins of adult disease.

Publication types

  • Review

MeSH terms

  • Adolescent
  • Animals
  • Arsenic / toxicity*
  • Behavior, Animal / drug effects
  • Birth Weight / drug effects
  • Child
  • Child Behavior Disorders / chemically induced
  • Child Behavior Disorders / epidemiology
  • Child, Preschool
  • Environmental Exposure / adverse effects*
  • Female
  • Humans
  • Infant
  • Infant, Newborn
  • Intellectual Disability / chemically induced
  • Intellectual Disability / epidemiology*
  • Memory Disorders / chemically induced
  • Memory Disorders / epidemiology*
  • Nervous System / drug effects*
  • Nervous System / growth & development
  • Nervous System / pathology
  • Neurotransmitter Agents / metabolism
  • Oxidative Stress
  • Pregnancy
  • Prenatal Exposure Delayed Effects / chemically induced
  • Signal Transduction / drug effects

Substances

  • Neurotransmitter Agents
  • Arsenic