Neurotoxin pandemic. Yes, you read that correctly and we are now in the middle of one as the list of industrial chemicals that can affect brain development in children continues to climb. In fact, in a February 2014 study published in The Lancet Neurology, researchers summarize the latest neurotoxins that might be influencing what they label as the “global, silent pandemic of neurodevelopmental toxicity.” In 2006, the research team released a systematic review which identified five industrial chemicals as developmental neurotoxins: lead, methylmercury, polychlorinated biphenyls, arsenic and toluene. Now an expanded up-to-date list has been given, grounded from new research that has since been gathered on chemicals linked to developmental disorders in children. This new list now includes six more problematic neurotoxins.
Research author Dr. Philippe Grandjean, Harvard School of Public Health, states: “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.”
Neurobehavioral concerns such as autism, ADHD, and dyslexia, affect millions of children worldwide with some diagnoses seem to be increasing in frequency. Environmental toxins are believed to make up about 60-70% of the cases of these disorders. Outlining specific compounds can be difficult, but research continues to mount and the researchers assume that even more neurotoxins remain undiscovered.
According to the authors, the frequency with which these chemicals present themselves in our everyday lives – even those that have been long banned – as well as the rising rates of developmental disorders in children, indicate that urgent change should immediately take place.
A child’s developing brain is extremely vulnerable to chemical exposures, both in utero as well as in the early childhood years. Unfortunately these changes can be lifelong. “During these sensitive life stages,” say the study’s authors, “chemicals can cause permanent brain injury at low levels of exposure that would have little or no adverse effect in an adult.”
Because this neurotoxin “pandemic” is quite disturbing, the authors highly recommend incorporating mandatory tests for chemicals. However, a common complaint has been that when one chemical is finally banned, seemingly another equally toxic and often untested chemical takes its place. More precise testing, though complicated to carry out, could address this major issue.
Dr. Grandjean says: “The problem is international in scope and the solution must therefore also be international. We have the methods in place to test industrial chemicals for harmful effects on children’s brain development—now is the time to make that testing mandatory.”
Neurotoxin Pandemic: 11 chemicals presenting strong evidence of a connection to neurodevelopmental disorders in children
- Lead. Lead has been extensively researched in terms of neurodevelopment and has been consistently linked to serious concerns one of which is low IQ. Even now countless water and soil sources are contaminated by lead because of improper disposal as well as the toxin being recycled from the ground to the water supply. Another way that lead still makes it into our bodies is through plumbing pipes – even if your water supply is pure many pipes have been soldered using lead. The side effects of lead exposure can be permanent which brings us to the conclusion that there really is no safe level of exposure.
- Methylmercury. The neurotoxin, methylmercury, affects neurological development of the unborn baby. Exposure often comes from the mother’s intake of fish containing high levels of mercury, according to the World Health Organization and the EPA. Most likely scientists and researchers will continue to debate the differences in toxicity between different types of mercury such as ethylmercury (thimerosal) or methylmercury (from fish). However, all would agree that mercury is definitely a potent neurotoxin.
- Polychlorinated biphenyls (PCB). This family of chemicals has routinely been associated with a reducing of cognitive function in infancy and childhood. PCBs are often present in foods, particularly fish, and can also be passed to babies through the mother’s breast milk. The key sex hormone that regulates and maintains the life cycles of a woman is estradiol. PCBs have been shown to interfere expressly with estradiol making it clear how it would be linked with developmental disorders in children. Chemicals that pose as xenoestrogens have been shown to cause breast cancer, uterine, and cervical cancers.
- Arsenic. When arsenic is absorbed through drinking water, this neurotoxin has been linked to decreased cognitive function in schoolchildren. Follow-up studies from the Morinaga milk poisoning incident have linked it to neurological disease in adulthood. The EPA also warns that Arsenic is still being released through different agricultural applications. It’s interesting to note that two Monsanto plants were placed on the EPA’s superfund list as priorities to be cleaned up for their release of arsenic-laden waste.
- Toluene. When used as a solvent, maternal exposure has been linked to brain development concerns as well as attention deficit in the child, according to the EPA and OSHA. The EPA warns that, “The highest concentrations of toluene usually occur in indoor air from the use of common household products (paints, paint thinners, adhesives, synthetic fragrances and nail polish) and cigarette smoke.”
- Manganese. Found in the drinking water in Bangladesh, for example, manganese has been linked to lower math scores, diminished intellectual function as well as ADHD. Even though manganese is a trace element and is important for good health, it is also used for steel production and is found in the exhaust of automobiles. High levels of manganese are shown to directly affect the Central Nervous System. In adult males manganese has shown to damage sperm.
- Fluoride. High levels of fluoride has been connected with a 7-point decrease in IQ in children. This clearly illustrates the fact that fluoride is detrimental to brain development and can lead to autism spectrum disorders and other mental issues.
- Chlorpyrifos and DDT (pesticides). These have been linked to structural abnormalities of the brain and neurodevelopmental concerns that can persist up to age 7. While these pesticides are banned in many parts of the world (U.S. included), they are currently used in many lower-income countries. Chlorpyrifos and DDT have recently been linked to Alzheimer’s disease.
- Tetrachloroethylene (AKAperchlorethylene). Tetrachloroethylene is linked to hyperactivity and aggressive behavior as well as an increased risk of psychiatric diagnosis. Mothers who work as in the professions of nursing, chemist, cleaner, hairdresser, and beautician had higher levels of exposure.
- The polybrominateddiphenyl ethers. Even though these flame retardants are currently banned, they are believed to be neurotoxins. Prenatal (both in male and female) exposure has been linked to neurodevelopmental disorders in the child.
- Bisphenol A (BPA), a common plastics additive, and phthalate, found in many cosmetics. BPA is an endocrine disruptor and is strongly suspected to affect neurodevelopment in children. It has currently been banned in baby bottles and sippy cups. Phthalates, common in many personal care products such as nail polish and hair spray, have been habitually linked to a shortened attention span and impaired social interactions in children.
Because of the prevalence of these neurotoxic chemicals in the environment, avoiding them can prove to be very difficult. These neurotoxins present themselves in food, water, cosmetics, receipt papers, and containers. Now, more than ever before, we must become “label readers”, if for no other reason than to protect our children from the often damaging effects of neurotoxins. You can find out more information on how to do this at the Environmental Working Group’s website and the article Endocrine Disrupting Chemicals – What You Need to Know.