The study suggests that toxic chemicals may be to blame and researchers say a new global prevention strategy to control the use of toxic substances is urgently needed. The report was published online in Lancet Neurology.
"The greatest concern is the large numbers of children who are affected by toxic damage to brain development in the absence of a formal diagnosis. They suffer reduced attention span, delayed development, and poor school performance. Industrial chemicals are now emerging as likely causes," said Philippe Grandjean, adjunct professor of environmental health at HSPH.
The report follows up on a similar review conducted by the authors in 2006 that identified five industrial chemicals as "developmental neurotoxicants," or chemicals that can cause brain deficits. The new study offers updated findings about those chemicals and adds information on six newly recognized ones, including manganese, fluoride, chlorpyrifos and DDT (pesticides), tetrachloroethylene (a solvent), and the polybrominated diphenyl ethers (flame retardants).
The study outlines possible links between these newly recognized neurotoxicants and negative health effects on children, including:
- Manganese is associated with diminished intellectual function and impaired motor skills
- Solvents are linked to hyperactivity and aggressive behavior
- Certain types of pesticides may cause cognitive delays