A Grain of Salt by Joe Schwarcz

Author:Joe Schwarcz
Language: eng
Format: epub
Publisher: ECW Press
Published: 2019-10-07T16:00:00+00:00

Food Wraps

We feel a little guilt every time we bite into that hamburger, sub, pizza, or hot dog. They may comfort the taste buds, but the fat, salt, cholesterol, and sugar they contain are not welcomed by the rest of the body. There is yet another issue that arises. It involves the packaging in which these fast foods are delivered. The hamburger is wrapped in some sort of paper, fries come in a cardboard container, and that pizza may be delivered in a box. Since all these items are greasy and moist, ordinary paper won’t do. It isn’t very appetizing to pick up a hamburger wrapped in paper soaked through with grease. That’s why various chemicals are used to provide moisture and grease resistance.

This, however, is not without controversy. Ideally, the packaging material should be both hydrophobic and lipophobic, meaning that it has the ability to repel both water and fat. That is quite challenging, but there is one class of chemicals, known as polyfluoroalkyl substances (PFASS), that is up to the task. Unfortunately, PFASS are also mired in controversy.

PFAS molecules are composed of a chain of carbon atoms to which fluorine atoms are attached. It is the fluorines on the periphery of the molecule that are responsible for repelling water and fat. But the presence of the carbon-fluorine bonds, which are very strong, also makes these molecules extremely resistant to degradation. The result is that they have been detected globally in water, soil, sediment, wildlife, and alarmingly, in human blood. Why the concern? Because some PFASS have been linked with thyroid disease, low birth weight, decreased sperm quality, higher cholesterol, as well as kidney and testicular cancer. It is important, however, to understand what “linked with” means.

While there is evidence that animals treated with polyfluorinated compounds exhibit the conditions mentioned, the doses are much higher than human exposure. Furthermore, exposure of animals to a single substance is a questionable model for extrapolating to effects in people who are exposed to literally thousands of compounds, both natural and synthetic, in their food on a daily basis. There are numerous interactions that can mitigate the effects seen with individual compounds. As far as humans go, high blood levels of PFASS, as can happen with occupational exposure, have been associated with disease. However, associations can never prove that there is a cause and effect relationship. For example, people may have high blood levels of these chemicals because they eat a lot of packaged fast foods, and it may be the diet that causes the problem.

Also, the specific molecular structure of the PFAS is important. Molecules that have a chain of eight carbons have been quite extensively studied and have been linked with health problems. Perhaps the most famous of these is perfluorooctanoic acid (PFOA), a compound that was widely used in the preparation of Teflon coatings before being phased out. It was not part of the final product, but during production, some PFOA was released into the environment. DuPont and its spin-off

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