Pesticides may damage human brain

Pesticides may damage brain growth in fetuses, infants and children

Many pesticides including organophosphates, carbamates, pyrethroids, ethylenebisdithiocarbamates, and chlorophenoxy herbicides may cause neurodevelopmental toxicity: European study

An Excerpt from:

Neurotoxicity of pesticides: a brief review

By Costa LG, Giordano G, Guizzetti M, Vitalone A.
Dept. of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98105, USA. lgcosta@u.washington.edu

• Pesticides are substances widely used to to protect crops against unwanted pests such as insects, weeds, fungi and rodents.
• Pesticides are not highly selective, and are also toxic to nontarget species, including humans.
• Many pesticides cause neurotoxicity.
• Insecticides, which kill insects by targeting their nervous system, have neurotoxic effect in mammals as well. This family of chemicals comprises the
  • organophosphates,
  • carbamates,
  • pyrethroids,
  • organochlorines
  • other compounds.

• Insecticides interfere with chemical neurotransmission or ion channels, and usually cause reversible neurotoxic effects, that could be lethal.
• Some herbicides and fungicides have also been shown to possess neurotoxic properties.
• The effects of pesticides on the nervous system may involve, or may contribute to
  • acute toxicity, as in case of most insecticides,
  • chronic neurodegenerative disorders, most notably Parkinson’s disease.

This brief review highlights some of the main neurotoxic pesticides, their effects, and mechanisms of action. [Modified for ease of reading: FEWW]

Section of neural tissue, showing three Lewy Bodies; protein inclusions characteristic of Parkinson’s Disease and other neurodegenerative disorders. (Source)

Potential developmental neurotoxicity of pesticides used in Europe [and elsewhere in the world].

A report by: Bjorling-Poulsen M, Raun Andersen H, Grandjean P.

Current requirements for safety testing do not include developmental neurotoxicity. The authors therefore undertook a systematic evaluation of published evidence on neurotoxicity of pesticides in current use, with specific emphasis on risks during early development. This report is based on a review of about 200 scientific reports worldwide about the pesticides and brain.

• Many pesticides that target the nervous system of insect pests may also be neurotoxic to humans because of the similarity in brain biochemistry.
• Developing brain may be particularly vulnerable to adverse effects of neurotoxic pesticides.
• Laboratory experimental studies using model compounds suggest that many pesticides currently used in Europe can cause neurodevelopmental toxicity. These include
  • organophosphates,
  • carbamates,
  • pyrethroids,
  • ethylenebisdithiocarbamates, and
  • chlorophenoxy herbicides.

• Adverse effects on brain development can be severe and irreversible, therefore, prevention should therefore be a public health priority.
• The occurrence of residues in food and other types of human exposures should be prevented with regard to the pesticide groups that are known to be neurotoxic.
• For other substances, given their widespread use and the unique vulnerability of the developing brain, the general lack of data on developmental neurotoxicity calls for investment in targeted research.
• While awaiting more definite evidence, existing uncertainties should be evaluated in regard to the need for precautionary action to protect brain development. [Abstract modified for ease of reading: FEWW]

Related Links:

• ‘Safe’ Pesticides: Worst in Poisonings