Air Pollution: Is it Making Babies Dumber?


In June, I wrote about Sanjay Gupta’s CNN special “Toxic Childhood“. The show told the story of a group of pregnant women who were fitted with special backpacks that tracked the chemicals in the air they breathed. The study produced concrete evidence of the number of potentially harmful chemicals being absorbed by the growing fetus.

While this information was clearly concerning, there wasn’t much concrete evidence of what exactly these chemicals might be doing to the growing fetus. If anything at all. The show featured some experts stressing that these chemicals, in the quantity people are exposed to them, “have never been shown to be harmful”

Well, it seems this period of ignorance may be coming to a close. It seems that the children whose moms inhaled more pollution while they were pregnant had lower IQs than babies whose mothers inhaled less.

So what does this mean?

The difference in IQ was not huge, but it was significant: the average was around four points lower in the babies whose moms had inhaled high levels of chemicals. This may not seem like a lot but study heads insist it’s enough of a difference to matter. Four points is apparently enough to affect schoolwork.

The specific chemicals involved were called Polycyclic Aromatic Hydrocarbons, found in fossil fuels. So they’re more of an issue in urban environments or other highly trafficked areas. The study was conducted in New York City and Krakau, Poland. The results were comparable in both locations, which strengthens the hypothesis.

This is not the first study linking prenatal chemical exposure to lowered childhood IQ. Similar results have been seen in studies of children with exposures to pesticides, mercury, and secondhand smoke. The IQ drop is about what one might expect from a low level lead exposure in childhood.

That comparison really freaked me out. There’s so much out there about the dangers of lead for kids and how to try to prevent it. The idea that the same kinds of damage could be done to children from things that we can’t prevent is really frightening. Let’s hope that this is taken to heart and inspires some serious environmental legislation. In the meantime, I guess you can work on holding your breath until that exhaust cloud passes…

photo: Dawn Ellner/flickr