What do flame retardants have to do with maternal and child health?

In case you missed it, it’s October(blog)fest here at the Duke Superfund Research Center. That means we’re going to be writing a LOT of posts all on a related topic – the effects of flame retardant chemicals on learning and behavior. Earlier this week one of our trainees (trainee=code for PhD student), Laura Macaulay, wrote about her work studying the impacts of flame retardants on the thyroid and its important hormones. She works on the exposure side of things, but later you’ll hear from another trainee who works on the behavioral side.

Why all of this hullabaloo about flame retardants and learning/behavior? Well, first of all, we’re not the only ones contributing to the fuss…flame retardants have been making the headlines for a while now. This is in part because flame retardants are found in a lot of consumer products (meaning most people are coming into contact with flame retardants on a regular, if not daily, basis), and in part because they’ve been shown to interfere with our bodies’ normal processes – stay tuned for a future post (or series of posts) about all the different sources of exposure!

Because of the link between flame retardants and neurodevelopment (the development of nerves and the nervous system), scientists are really digging into maternal and child exposures to flame retardants.

A recent example is Duke faculty member Dr. Susan Murphy’s work on the interaction between genes and the environment and how this drives fetal development in the womb (listen to or read her interview on NPR). This interaction is called epigenetics – or how individual genes can be switched on and off by certain chemicals (like flame retardants or nutrients) and alter the normal development of a fetus.

But epigenetics aren’t the only way that flame retardants my impact learning and behavior. As we’ve mentioned before, there’s the thyroid and its related hormones. The thyroid and thyroid hormones are part of a larger bodily system called the endocrine system. Not only can flame retardants interfere with the thyroid, but they can disrupt normal function of other parts of the endocrine system – we call these endocrine disruptors (or EDs). It’s as endocrine disruptors that flame retardants can affect neurodevelopment. And since the programming for normal development of the nervous system is set really early on (in the womb or as a child), understanding health effects associated with maternal and child exposures to flame retardants is important.

So how are soon-to-be mothers exposed, or anyone else for that matter? Everyday items, including furniture, have chemicals in them that may present a risk to one’s health when exposed to them over a long period of time. Polybrominated diphenyl ethers, or PBDEs, are a flame retardant chemical used in furniture and other household items, including electronics, until they were  largely phased out of use over the last few years (voluntarily by a few manufacturers) and banned in California in 2006 because of known negative health effects.

Tracey Woodruff, the director of a program at UCSF that focuses on reproductive health, has been one of the researchers studying the level of PBDEs in blood. (Our own Dr. Heather Stapleton is also studying PBDEs in blood). One of Woodruff’s most recent papers, published in Environment Science & Technology, shows decreasing PBDE levels in women from 2008-2012. It’s pretty outstanding that scientists have already measured a decrease in the levels of PBDEs in blood in response to regulations.

Measuring PBDEs in blood gives us a good idea of the amounts of PBDEs pregnant women are exposed to and how that may be affecting the health of children, but even with the decrease in blood levels it’s also important to continue studying the mechanisms of toxicity (by looking at rodents and fish) and the specific learning and behavioral effects of exposure.

Along this line, here are some things to be on the lookout for through the rest of October:

  1. Firemaster 550 (a specific flame retardant)
  2. Results from adult behavioral tests
  3. Neural and behavioral toxicity tests
  4. Sources of exposure to flame retardants