In 2006, two researchers, Philippe Grandjean and Philip Landrigan, conducted a review of existing studies and posited that certain industrial chemicals could contribute to neurobehavioral effects. It appears that they have updated their 2006 work and are recirculating it under the title “Neurobehavioural effects of developmental toxicity,” which was published yesterday in the journal The Lancet.
The causes of neurobehavioral disorders like autism, attention deficit disorder and childhood brain development are topics that unquestionably deserve further study and review. However, this report has several serious flaws that undermine its credibility and usefulness in advancing understanding of these important issues.
First, the report ignores the fundamental principles of exposure and potency. In other words, the authors disregard important factors like how chemicals are used, whether children are actually exposed to them, at what level they are exposed and for how long. Through extensive scientific research we already know a great deal about specific chemicals and how they interact with the body. In spite of the authors’ omissions about actual exposures, they call for all chemicals to go through extensive testing specifically to screen for neuro effects.
Second, the authors’ two reports focus largely on 12 chemicals and heavy metals that are well understood to pose potential risks to children when exposures exceed established thresholds; that are highly regulated and/or are restricted; or that are being phased out. They then extrapolate that similar conclusions should be applied to other chemicals that are more widely used in consumer products without providing any evidence to support their claims. Such assertions do nothing to advance true scientific understanding and only create confusion and alarm. The authors’ efforts to instill fear, not based on scientific evidence, are akin to closing schools in Southern California because New York City is getting 10 inches of snow. Where is the evidence of harm or concern? A perfect example is the authors’ inflammatory media comments about phthalates, a data-rich family of chemicals with a 50-year track record of safe use that regulators have reviewed for many important applications.
The authors’ exaggerated claims were called out, “in comments prepared by the Science Media Centre, epidemiologist Jean Golding of the University of Bristol accused the pair of issuing ‘scare’ statements.”
“To implicate high fluoride, which they quote as one of the new chemicals…they quote only one paper; this only compares the mean IQs of children in villages with different levels of fluoride, with no allowance made for any other differences, and no actual measurement of fluoride in individual children and comparison with their IQs. This is not good evidence.”
The authors ultimately argue that an entirely new, international framework is needed to test and track information specifically about neurotoxicity, backed by extensive new testing requirements. But rather than creating a new cumbersome global bureaucracy, shouldn’t we focus on implementing an efficient, agile and effective approach to screening and regulating chemicals based on the actual risks they may pose?
This brings me to one point where we agree with the authors: the U.S. does need a new, more modern and more effective system to regulate chemicals. While there are protections in place to promote the safe use of chemicals, the primary law that regulates chemicals is nearly 40 years old and needs an update.
Legislation has been proposed in Congress that would do just that by requiring all chemicals in commerce be evaluated by the U.S. EPA; giving regulators more authority to require further testing (including testing for neurobehavioral effects, if warranted); and making more data about chemicals available to the public. The Chemical Safety Improvement Act (CSIA) would go a long way toward giving consumers and the public health community more information and more confidence that chemicals in consumer products are safe for their intended uses, and it would help dispel common myths like the one repeated by the authors that there are 80,000 chemicals in widespread use that have not been tested. Unfortunately, the legislation has been tangled up in partisan wrangling that is preventing progress.
We appreciate contributions to the discussion about childhood neurobehavioral and developmental challenges. At the same time we would hope that well-established and respected researchers like Drs. Grandjean and Landrigan would take greater care to adhere to sound scientific principles rather than engaging in what can only be called conjecture. We would also hope that the authors will join us in calls for Congress to put partisan politics aside and pass the CSIA.