Dangerous inheritance: When chemicals pass from mom to baby

July 23, 2013

I can only imagine the joy parents must feel when they look at their baby’s face and see something of themselves in it. My own father proudly takes credit for my blue eyes while my mother insists that I got my big smile from her. Like so many of us, I inherited some of my best traits from my mom, but I also inherited something hidden and far more troubling—the burden of chemicals in her body.

Everyone’s first environment is the womb and many toxics can harm babies before they take their first breath by traveling through mom’s body and crossing into the developing child. The flame retardant chemicals polybrominated diphenyl ethers (PBDEs) can do just this, and yet another recent study documents how higher levels of PBDEs in moms when they are pregnant are linked to lower IQs and attention problems in their children.

My background is in public health, so I know a lot about the ways chemicals can enter people’s bodies and the associated health problems, but I have often wondered exactly how these flame retardant chemicals cause their harmful effects. This excellent video animation by Leah Moak from the University of Chicago at Illinois Biomedical Visualization program shows the process by which a mother’s exposure to PBDEs disrupts fetal brain development.

The issue is that the physical shape of PBDEs bears an unmistakable resemblance to a human thyroid hormone called T4. Hormones are chemicals that act like the air traffic controllers of the body, broadcasting signals that start, stop, and moderate processes throughout the body. The T4 hormone normally controls brain development, but PBDEs are hijackers that take the place of these hormones and block them from doing their job. This is how prenatal and childhood exposures to PBDEs interrupt the processes of building a brain, resulting in consequences like lowered IQ and hyperactivity. But the brain is not the only part of the body that is affected by these chemicals; many of the body’s systems rely on T4 to develop normally.

New research from Sweden suggests that there is also a connection between prenatal PBDE exposure and low birth weight in babies, especially baby boys. Researchers in Sweden found that moms with higher levels of PBDEs in their bodies had babies with lower birth weights. Babies with low birth weight are at increased risk for weight issues, hypertension, and metabolic problems associated with diabetes later in life, representing another example of how contact with toxic chemicals at crucial stages of development can impact the way our bodies function for the rest of our lives. And it is becoming increasingly clear that if we are going to protect children’s health, we have to start with Mom and we have to start well before she even thinks about having kids, as many toxics do not leave our bodies for years, if ever.

But there is some good news too! Namely that policy changes actually do have an impact on our bodies’ burden of chemicals. A new study looking at the levels of PBDEs in newborns from 1997 through 2011 found that PBDE levels stayed relatively constant from 1997 to 2002 and then began to drop. This drop in PBDE levels correlates with the phase out of their production, which means that responsible toxics policy really will start improving our health and the health of our kids.

Children rely on adults for just about everything, including their voice in politics and industry. They can’t vote and a lot of them are too young to even write a letter to a company that uses toxic chemicals asking them to stop. It is up to us to speak up on their behalf and use our power to protect them. So next time you head to the ballot box or decide which product to purchase, remember that your choices have the potential to improve children’s lives.