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Environmental Factor

Environmental Factor

Your Online Source for NIEHS News

August 2016

Project TENDR focuses on common chemicals affecting neurological development

Leading scientists and experts called for reductions in chemical exposures that affect development of the brain.

More than two dozen leading scientists, medical experts, and children’s health advocates called for eliminating or reducing chemical exposures that affect growth and development of the brain. The group is part of Project TENDR: Targeting Environmental Neuro-Developmental Risks.

The “The TENDR Consensus Statement,” published July 1 in the journal Environmental Health Perspectives, focused on toxic chemicals linked to neurodevelopmental disorders, such as autism, attention deficit hyperactivity disorder, and intellectual disability.

New data on risks to brain development

“It’s the first time so many leaders in public health, science, and medicine agree on the message from the scientific evidence — that toxic chemicals are harming our children’s brain development,” said TENDR Co-Director Irva Hertz-Picciotto, Ph.D., Ph.D., who directs the NIEHS Environmental Health Sciences Core Center at the University of California at Davis. “Ten years ago, this consensus wouldn’t have been possible, but the research is now abundantly clear.”

The statement draws on 65 scientific studies and reports showing that chemicals and pollutants, including those listed below, contribute to learning, intellectual, and behavioral impairments in children.

  • Organophosphate pesticides
  • Polybrominated diphenyl ether (PBDE) flame retardants
  • Combustion-related air pollutants, which generally include polycyclic aromatic hydrocarbons (PAHs), nitrogen dioxide, and particulate matter
  • Lead
  • Mercury
  • Polychlorinated biphenyls (PCBs)

Widespread exposures

The authors cite research demonstrating that most pregnant women show detectable levels of PBDEs, PAHs, phthalates, PCBs, lead, and mercury, as well as other chemicals.

“In light of this extensive evidence and continued widespread exposure, the risks for learning and developmental disorders can likely be lowered through targeted exposure reduction,” the authors wrote. They called for regulators, businesses, policymakers, and health professionals to take steps to reduce or eliminate exposures.

Vulnerable period with expensive impacts

Neurotoxicologist Susan Schantz, Ph.D.,(https://www.niehs.nih.gov/research/supported/translational/peph/grantee-highlights/2016/index.cfm#a788411) director of the NIEHS-funded Children's Environmental Health Research Center at Illinois, explained in a press release why gestation and early childhood are vulnerable periods.

“The human brain develops over a very long period of time, starting in gestation and continuing during childhood and even into early adulthood,” Schantz said. “But the biggest amount of growth occurs during prenatal development. The neurons are forming and migrating, and maturing and differentiating. And if you disrupt this process, you’re likely to have permanent effects.”

The authors asserted that exposure reductions would have economic and health benefits. “The economic costs associated with neurodevelopmental disorders are staggering,” the statement said, citing published research, such as a 2009 study that found for every $1 spent to reduce exposures to lead, society would benefit by $17–$221.

Important steps forward

Project TENDR noted that revisions to the Toxic Substances Control Act, which were signed into law by President Obama days before publication of the consensus statement, are a positive step.

Meanwhile, the organization’s website offers specific actions anyone can take to reduce exposures to themselves and their families. Suggestions include choices about food, water, and home and personal care products; reductions in dust and dirt levels; and steps to limit household pests. The site also provides resources on environmental exposures and child health.

Signers of the consensus statement included several NIEHS grantees, as well as Linda Birnbaum, Ph.D., director of NIEHS and the National Toxicology Program. “NIEHS is pleased to support research by in-house scientists and grantees that provides decision-makers with solid information about health concerns related to environmental exposures,” she said. “The evidence of risks to developing fetuses and young children from these chemicals gets clearer every day.”

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