To commemorate World Environmental Health Day this year and its focus on children’s environment and health, CHE is publishing a series of short essays from partners who are leaders in children’s environmental health.
Climate change and chemical pollution are serious challenges that require tough decisions, and the solutions will depend on human ingenuity. In other words, we need smart people to help clean up the problems that present and previous generations have created.
But counter to this notion, we are promoting toxic chemicals that can damage human brain development. So we are essentially generating a vicious circle: industrial chemicals damage the development of the brains of the future that should have helped us design safer uses of chemicals that would not endanger the nervous system of the next generation.
We already know that more than 200 industrial chemicals can detrimentally affect brain functioning in adults. Although we have so far gathered enough evidence only on a dozen or so substances that can damage a child’s developing brain, we know that such toxicity occurs at much lower doses than those that affect the adult brain. Still, only a few of these chemicals have so far been regulated in order to protect the brains of the next generation.
The consequences are dire. Adverse effects on brain development are likely to be permanent. Some cases may be severe enough to trigger a diagnosis of ADHD, cerebral palsy, autism, or other serious disorders, but the vast majority of children will suffer minor functional losses in cognitive functioning, which can involve memory, language skills, problem-solving abilities, or some other aspect of higher mental functions. The total loss in terms of IQ points has been calculated to be many millions of points. The societal value of smart brains is difficult to assess but the costs due to lead, mercury and pesticides have been calculated to correspond to an annual loss of many billions of dollars.
The greatest loss is of course incurred by children and adults who never got the chance to fully develop their skills and talents. But the societal cost also includes the loss of overall intelligence—the smart ideas and initiatives that we need to make this world a safer place, one that allows brains to develop without toxic interference.
We already know of initiatives that are well justified and could be applied right now to protect the brains of the future. Stricter limits for usage and dissemination of brain-toxic chemicals should be applied to reduce or eliminate our exposure to them. As relatively few chemicals have been tested for such effects so far, we must initiate proper testing of chemicals new and old to determine whether they result in any risks. Such testing is being discussed in the European Union, but must be done internationally. Is there a better purpose than protecting the brains of our children and grandchildren? I would think not, and we definitely need brains in the future who are smarter than we are.
Dr. Grandjean is professor and chair of Environmental Medicine at the University of Southern Denmark and adjunct professor of Environmental Health in the Department of Environmental Health at Harvard School of Public Health. He has devoted his career to studying how environmental chemicals affect children and their brain development.