More than 30 congressional staff and other stakeholders attended a briefing Dec. 17, 2015, to hear the latest findings from NIEHS research on endocrine disrupting chemicals and their effects on health. Speakers addressed the most susceptible life stages, effects of low-dose exposures, and the need for more prevention strategies.
The briefing was hosted by Sen. Dianne Feinstein, D-Calif., and co-sponsored by the Friends of NIEHS and the Endocrine Society.
Exposures and susceptibility both vary
Linda Birnbaum, Ph.D., director of NIEHS and the National Toxicology Program, began the briefing by describing how even low doses of chemicals can affect health, and that exposures vary across time. “Your exposures can change day to day, as well as minute to minute,” she said.
Studies show that developmental stages — especially before birth and during infancy and childhood — and old age are particularly susceptible periods because organs are forming, gene expression programs are being established, and epigenetic reprogramming is occurring. “Timing of exposure can determine the impact,” Birnbaum said.
Animal studies show importance of neonatal period
NIEHS-funded researcher Shuk-Mei Ho, Ph.D., from the University of Cincinnati College of Medicine, discussed links between early life exposures and incidence of disease in later life and across generations.
She said her studies found that mice exposed to bisphenol A (BPA) after birth experienced a higher incidence of cancer compared to mice with no exposure. Her lab is now looking at how dietary factors may affect sensitivity to toxicants, as well as the effect of BPA exposure on later generations.
Children’s exposure studies
Jennifer Lowry, M.D., a pediatrician from Children’s Mercy Hospital in Kansas City, Missouri, highlighted the importance of understanding the exposures children face, and the need for more research on how to limit or prevent harmful exposures.
Lowry referred to the Centers for Disease Control and Prevention (CDC) National Report on Human Exposure to Environmental Chemicals, which is a series of ongoing assessments of the U.S. population’s exposure to environmental chemicals. According to Lowry, CDC is finding high prevalence of chemicals in the population they tested, including polybrominated diphenyl ethers, used as flame retardants; BPA, used in plastics; and perfluorinated chemicals, used in a variety of applications, including nonstick cookware coating.
“We know that exposures and adverse health outcomes can happen concurrently. And the research needs to continue,” Lowry stressed, “because we don’t know the extent [to which] these effects are occurring.”
The congressional staff responded with questions about the effects of preterm birth and low birth weight; how a father’s exposures may affect the health of his children; how studies take into account exposures to multiple chemicals; and other topics.