Doctors used to think of the placenta as a perfect barrier — a mom-to-baby filtering system that allowed all the good stuff to pass and kept the bad stuff out. Now we know that’s not true at all: air pollutants, pesticides, plastics chemicals — when scientists take sample of a baby’s umbilical cord after birth, they find evidence of hundreds of unsavory elements.
That doesn’t mean they are all damaging, of course. Scientists like Federica Perera at the Columbia Center for Children’s Environmental Health are trying to measure how the chemicals in mom’s world actually affect the life growing in her womb.
Here’s the latest piece of the puzzle. To give you a hint, it doesn’t make me feel good about living in the land of six lane highways:
Perera and her colleagues measured the traces of exposure to polycyclic aromatic hydrocarbons (PAH) and other products of combustion in newborns’ cord blood. These pollutants pass through the placenta and are thought to bind to the DNA of a growing baby.
The babies with the highest level of exposure to the traffic-related pollutants had more symptoms of behavioral problems and symptoms of anxiety and depression when they were five-years-old than those with lower exposures.
Previous studies in which moms wear a sample-collecting backpack device while pregnant to measure their exposure to toxins have linked high traffic pollutant exposure to cognitive problems.
My question is: we can’t know that the traffic pollution is what directly caused behavioral problems, of course — it’s a correlation only. But I also wonder how you would sift apart the effects of traffic pollution during pregnancy from the effects of those same children spending years in high traffic areas after they’re born? Then again, we know that a fetus is developing and growing new neurons at such a high rate, it makes sense that pollutants would make their mark on a rapidly developing brain.
Maybe this is a perfect reason to take a break when you’re pregnant (I know, we don’t really allow ourselves that), spend time outside the city — in the clean mountain air.