Just 10 years ago, it wouldn’t have been possible to bring leading physicians, scientists and advocates together in a consensus on the links between toxic chemicals and neurological disorders, says Maureen Swanson. But with the science increasing “exponentially,” she said the time was ripe for a concerted call to action.
Swanson is co-director of Project TENDR (Targeting Environmental Neuro-Developmental Risks), a coalition of doctors, public health scientists and environmental health advocates who joined forces in 2015 to call for reducing chemical exposures that interfere with fetal and child brain development. This past summer in July, after more than a year of work, the group published its TENDR Consensus Statement in Environmental Health Perspectives, laying down a foundation for developing future recommendations to monitor, assess and reduce neurotoxic chemical exposures. The consensus concludes that a new framework for assessing such chemicals is desperately needed, as the “current system in the United States for evaluating scientific evidence and making health-based decisions about environmental chemicals is fundamentally broken.”
Swanson said the consensus statement is a first of its kind, adding that it’s “unprecedented” to have such a breadth of scientists come together and agree that the “science is clear” on toxic chemicals and neurodevelopmental disorders.
“Part of the urgency is because these toxic chemicals are in such widespread use and exposures for children and pregnant women are so widespread — they’re just ubiquitous,” Swanson, who also directs the Healthy Children Project at the Learning Disabilities Association of America, told me. “The urgency is also in seeing the trends in learning and developmental disorders and cognitive and behavioral difficulties — they’re problems that only seem to be increasing.”
According to the consensus statement, which Swanson said involved hundreds of studies and “countless hours” and reviewing and assessing the evidence, the U.S. is home to an alarming increase in childhood learning and behavioral problems, with parents reporting that one in six American children are living with some form of developmental disability, such as autism or attention deficit hyperactivity disorder. That statistic is an increase of 17 percent from a decade ago. The statement offers examples of toxic chemicals that can contribute to such disorders and lays out the argument for a new approach to chemical safety.
For example, the statement notes that many studies offer evidence that “clearly demonstrates or strongly suggests” adverse neurodevelopmental toxicity for lead, mercury, organophosphate pesticides, combustion-related air pollution, PBDE flame retardants and PCBs. Lead, as Swanson noted, is a perfect example of a widely used chemical that contributes to cognitive problems and intellectual impairment — “and yet it’s still everywhere, in water pipes, in cosmetics. We thought we’d done a good job of eliminating lead problems, but we haven’t done enough,” she said. Another prime example are chemical flame retardants, one of the most common household toxic exposures associated with neurodevelopmental delays in children.
“Of course these disorders are complex and multifactorial, so genetics plays a role, nutrition does and social stressors do,” Swanson told me. “But the contribution of toxic chemicals is a piece that we can prevent. We can do something about this part to decrease the risk to children.”
On taking action, the consensus argues that the current system for evaluating the human health effects of chemicals is “broken,” noting that of the thousands of chemicals now on the market, only a fraction have been tested for health impacts. The consensus reads:
Our failures to protect children from harm underscore the urgent need for a better approach to developing and assessing scientific evidence and using it to make decisions. We as a society should be able to take protective action when scientific evidence indicates a chemical is of concern, and not wait for unequivocal proof that a chemical is causing harm to our children.
Evidence of neurodevelopmental toxicity of any type — epidemiological or toxicological or mechanistic — by itself should constitute a signal sufficient to trigger prioritization and some level of action. Such an approach would enable policy makers and regulators to proactively test and identify chemicals that are emerging concerns for brain development and prevent widespread human exposures.
As many of you know, President Obama signed the Frank R. Lautenberg Chemical Safety for the 21st Century Act into law in June, reforming the woefully outdated federal Toxic Substances Control Act (TSCA), which hadn’t been updated since 1976. And while TSCA reform is certainly a “step in the right direction,” Swanson said the sheer backlog of chemical safety testing as well as the pace of testing set forth in the new law means the process of reducing or removing toxic exposures will likely be incredibly slow — and even that’s still dependent on whether the U.S. Environmental Protection Agency is fully funded to implement TSCA reform.
“TSCA reform by itself is insufficient to address the magnitude of these problems,” she said, noting that pesticides are outside of TSCA’s and the new law’s jurisdiction.
In turn, consensus authors called on regulators to follow scientific guidance when assessing a chemical’s impact on brain development, with a particular emphasis on fetuses and children; called on businesses to eliminate neurotoxic chemicals from their products; called on health providers to integrate knowledge about neurotoxics into patient care and public health practice; and called on policymakers to be more aggressive in reducing childhood lead exposures.
The problem of harmful chemical exposures can seem like an overwhelming one — “nobody can shop they’re way out of this problem,” Swanson said — but there are steps that can be taken right away to reduce exposures. For example, Swanson noted that when the U.S. phased out the use of lead in gasoline, children’s blood lead levels plummeted. Similarly, after Sweden banned PBDEs in the 1990s, levels of the chemical found in breast milk dropped sharply.
In terms of next steps, Swanson said Project TENDR will continue reaching out to policymakers, health professionals and businesses on how to work together toward safer chemical use and healthier children.
“There’s a lot we can do that can make a substantial difference in a relatively short time frame,” Swanson told me. “Our key message is that this is problem we can do something about. There’s reason for alarm, but also reason to get working and take care of it collectively so that our children are not at greater risk for neurodevelopmental disorders.”
To download a full copy of the Consensus Statement, as well as find tips on reducing harmful exposures on an individual level, visit Project TENDR.
Kim Krisberg is a freelance public health writer living in Austin, Texas, and has been writing about public health for nearly 15 years.