Environmental Toxins That Affect Brain Development

 Author: Dr. Stephen Chaney

 In a recent review, Drs. Grandjean and Landrigan (The Lancet Neurology, 13: 330-338, 2014) identified 12 toxic chemicals which are abundant in our environment and are developmental neurotoxins.

These are all chemicals that damage brain development. They can cause decreases in IQ and aggressive or hyperactive behavior in children – and that those changes may be permanent.

Let’s look at these developmental neurotoxins and where they are found.

The Dirty Dozen

In their review Grandjean & Landrigan identified 6 developmental neurotoxins that were known in 2006, and 6 more chemicals that have been confirmed to be developmental neurotoxins between 2006 and 2023.

Developmental Neurotoxins Known in 2006 and their sources:

• Lead
  

• Main Sources: paint, gasoline, solder and consumer products such as toys & jewelry

• Current status: Lead has been banned in paint since 1978 and from gasoline since 1996. Millions of houses still contain lead paint. Other current sources are inexpensive toys and costume jewelry imported from China and other countries without tight regulations.
• The EPA estimates that 1 million children in the US are affected by elevated lead levels.

• Methylmercury
  

• Main Sources: discharges into air & water from coal-burning power plants, mining, pulp & paper industries.

• Polychorinated biphenyls (PCBs)
  

• Main Sources: transformers and many commercial products

• Current status: Banned in 1979, but continues to be a common environmental contaminant because this group of chemicals is very long-lived.

• Arsenic:
  

• Main Sources: extraction of metals from rock (smelting), algaecides, herbicides, pesticides and pressure-treated wood.

• Current status: Pressure treated wood banned in 2003 for residential use. Still found in some playgrounds and older buildings.

• Toluene:
  

• Main Sources: gasoline. It is also a solvent for paints, paint thinners, spot removers, adhesives, antifreeze, & some consumer products like fingernail polish removers.

• Current status: Common in consumer products. Read labels and make sure windows are open if you use.

Developmental Neurotoxins Identified Since 2006 and their sources:

• Manganese
  

• Main Sources: municipal wastewater discharge, emissions generated during alloy, steel & iron production, emissions from burning of fuel additives

• Flouride
  

• Main Sources: naturally elevated in groundwater in certain regions, added to municipal water supply, most bottled beverages and toothpaste.

• The American Academy of Pediatrics has warned that children drinking fluoridated water, fluoridated beverages, using fluoridated toothpaste and receiving fluoride treatments for their teeth may be receiving excess fluoride.

• Chlorpyrifos
  

• Main Sources: insecticide

• Current status: Banned for use in homes in 2001. Still one of the most widely used insecticides in agriculture.

• DDT
  

• Main Sources: insecticide

• Current status: Banned for use in this country in 1972. DDT and its breakdown products still found in our water supply. DDT still in use in agriculture and insect control in some countries.

• Trichloroethylene (TCE)
  

• Main Sources: widely used in dry cleaning fabrics, the textile industry and metal degreasing

• Current status: Found in groundwater due to discharge from factories and dry cleaners.

• Polybrominated diphenyl ethers (PBDEs)
  

• Main Sources: flame retardants – used in building materials, electronics, mattresses & household furniture, plastics, polyurethane foams & textiles.

• Current status: Readily leached into the environment. Found in dust, water, food & human breast milk

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.