Millions of children are affected worldwide by neurodevelopmental disorders such as attention-deficit hyperactivity disorder (ADHD), autism, mental retardation, dyslexia, and other learning and cognitive disabilities. A variety of industrial chemicals resulting in developmental neurotoxicity have been identified. These include (and the list is not exhaustive):
- Bisphenol A
- Dichlorodiphenyltrichloroethane (DDT)
- Polybrominated diphenyl ether (PBDE)
- Polychlorinated biphenyl
Neurodevelopmental disabilities cause significant morbidity in the affected individuals throughout their life, including behavioral issues, poor performance at school and work, and decreased overall quality of life. The consequences are not confined to individual families alone, but stretch across entire communities and societies as well.
The detrimental effects of developmental neurotoxicity include preterm births, ADHD, autism spectrum disorders, pediatric bipolar disorder, and postnatal traumatic brain injury. Apart from these, an exposure to unsafe neurotoxins can also have wide-ranging and economic consequences for the societies from antisocial behavior, increased violence and criminal activities, and early substance abuse.
The exact causes of such neurodevelopmental disorders are unknown. Vast number of studies has concluded that there may be an involvement of genetic and/or environmental factors. If the environmental factors are well-recognized and managed appropriately, it would result in decreasing the incidence of neurodevelopmental disorders caused by industrial toxins and pollutants.
A Lancet Neurology study published in 2014, titled “Neurobehavioural effects of developmental toxicity” by Philippe Grandjean and Philip J Landrigan propose a coordinated international strategy that focuses on:
- Legally mandated testing of existing industrial chemicals and pesticides already in commerce, with prioritisation of those with the most widespread use, and incorporation of new assessment technologies.
- Legally mandated premarket evaluation of new chemicals before they enter markets, with use of precautionary approaches for chemical testing that recognise the unique vulnerability of the developing brain.
- And, the formation of a new clearinghouse for neurotoxicity as a parallel to the International Agency for Research on Cancer.
The setting up of an international clearing house on neurotoxicity is to protect brain development during early fetal and child growth and promote optimum brain health. The panel recommendations for the clearing house include to:
- Screen industrial chemicals present in human exposures for neurotoxic effects so that hazardous substances can be identified for tighter control
- Stimulate and coordinate new research to understand how toxic chemicals interfere with brain development and how best to prevent long-term dysfunctions and deficits
- Function as a clearinghouse for research data and strategies by gathering and assessing documentation about brain toxicity and stimulating international collaboration on research and prevention
- Promote policy development aimed at protecting vulnerable populations against chemicals that are toxic to the brain without needing unrealistic amounts of scientific proof
(Source: Grandjean, P., & Landrigan, P. J. (2014). Neurobehavioural effects of developmental toxicity. The lancet neurology, 13(3), 330-338.)