Thursday, July 05, 2007

Our bodies, the ultimate transformers: PFOA and other perfluorinated chemicals in our bodies

Our bodies are constantly working, transforming chemicals from one form to another like that bagel and cream cheese I had for breakfast into something hopefully more useful or, the chemicals from that greaseproof food-packaging paper into something more toxic. Whoa. What?

A few posts back I wrote about perfluorinated chemicals – known as PFOA and PFOS - used for waterproofing and nonstick pans. Then I added a post about PFOA and popcorn bags. Now it’s even more insidious and complicated than being exposed to just PFOA. Considering recently reported concentrations of these chemicals in human blood, Jessica D’Eon and Scott Mabury, in a study just published in Environmental Science and Technology suggest that concentrations in humans are likely the result of “exposure to current-use fluorinated materials and not the historical load present in the environment,” (Certain perfluorinated chemicals have been phased out of use by major producers once recognized as human and environmental contaminants.)

These current-use chemicals, particularly those used to manufacture waterproof or greaseproof paper (think microwave popcorn,) known as polyfluoroalkyl phosphate surfactants or PAPs, can be transformed once transferred from say, that greasy microwave popcorn bag to our fingers or popcorn and then to our guts, not only into PFOA (which a recent draft assessment by EPA suggests is a carcinogen) but also chemical compounds which might be more immediately toxic.

Referring to the byproducts of metabolism D’Eon and Mabury write,“Due to their inherent reactivity, exposure to these transient metabolites is likely of greater toxicological concern than exposure to PFCAs [which includes PFOA] alone.”

Huh. Ain’t that funky now.

Of course further work is necessary before the potential impacts of these kinds of exposures can be fully understood, including a better understanding of how (and how much of) these chemicals migrate into food, what kinds of food are most important for this kind of exposure, and how much of these foods we consume. Microwave popcorn anyone?

You can find the full article, in issue 41, of Environmental Science & Technology, pages 47-99-4805.

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