Precocious Girls and Dumb Boys: Are Phthalates to Blame?

The authors of two just-released studies put forth some frightening conclusions: The more phthalates children are exposed to, the more likely girls are to experience early-onset puberty, and the more likely boys are to have a couple of points shaved off their IQs.

Phthalates are the ubiquitous plastic softeners found in everything from shower curtains to nail polish, so completely eliminating them from your immediate environment would probably require that you live in a hemp yurt and eat out of gourds. Before you go that far, there are a few things you need to know about these studies:

First, the negative effects were only apparent (i.e., statistically significant) in kids who had the absolute highest levels of phthalates in their blood. There are two ways to interpret that; one is that the statistical power of these studies wasn't all that great — the study on girls included 1100 subjects and the one on boys included less than 700, which isn't a lot when you're asking as many questions as these two studies were.

The other way to interpret the weak association of phthalates and a negative outcome is that phthalates, like all hormone mimics, can have some pretty subtle effects on the body, and what matters is cumulative exposure. In other words: if you don't want your kid to end up like the children on the wrong end of the bell curve in these studies, you should probably try to avoid phthalates, knowing, of course, that you won't be able to do it completely.

The complexity of this issue could fill ten blog posts, so I'll try to sum it up with a list of further reading for those who are genuinely concerned.

While there is substantial evidence that phthalates can mess with development and fertility in animals, the human studies on the subject are far from conclusive. The American Chemistry Council would like you to believe that Phthalates are harmless and that the EPA's forthcoming scientific assessment of their threat is motivated more by the public's fear than by the peer-reviewed literature.

Whatever the outcome of the EPA's inquiry, the U.S. is currently moving toward a European-style "precautionary principle" in the way that we regulate chemicals, which "shifts the burden to the manufacturer to prove that a product is safe before it can be marketed, rather than demonstrating that it is not unsafe."

That's probably not a bad idea, considering that phthalates and other 'endocrine disruptors' have also been linked to ADD and possibly even Autism. Not to mention some of the really bad outcomes chemicals have had before they were eventually pulled from the marketplace.

S.C. Johnson is the first manufacturer to pledge to remove phthalates from their household products.

Personally, having a newborn at home, we try to store our food in glass, buy foods in glass containers and avoid canned food (because of a related issue - BPA) but only a blood test could tell you whether or not your efforts are making a difference.

Photo credit: Charlotte Morrall