Consider a box of microwaveable, butter-flavored popcorn. The label assures buyers it has zero grams of trans-fat and “zero mg cholesterol.” But the ingredients list fails to mention that the savory butter taste and mouth-watering aroma comes courtesy of diacetyl, a flavoring long known by pulmonary specialists to cause “bronchiolitis obliterans,” a disease that causes the small airways in the lungs become to become swollen, scarred and, eventually, obliterated.
Victims can breathe in deeply but have severe difficulty exhaling. More commonly known as “popcorn worker’s lung,” the disease has sometimes led to the death of those who labor in popcorn factories or plants that make candy and pastries, even dog food, where diacetyl gets used as a flavoring.
The canary in the coal mine for the rest of us was Wayne Watson of Centennial, Colo. When Watson was diagnosed with popcorn worker’s lung, his physicians alerted federal agencies to say the threat had leaped beyond factory walls to consumers’ homes. The resulting public alarm swiftly led the largest U.S. makers of microwave popcorn to announce they were pulling diacetyl from their mix of ingredients.
In nature, diacetyl occurs in butter, cheese and some fruits at low levels that pose no danger. The popcorn companies were breaking no law by using diacetyl; the Food and Drug Administration approved its use. And Wayne Watson had put himself at unusual risk; he dubbed himself “Mr. Popcorn” because he devoured two or three bags every day for ten years.
He especially loved to fill his lungs with a deep inhalation of the buttery cloud of aroma released the moment he ripped open a freshly popped bag – in other words, the strongest dose possible. That was a recipe for medical disaster.
When heated, diacetyl becomes a vapor, the form that poses a danger to lungs. If breathed in over long periods, concentrated doses of this very vapor leads to popcorn worker’s lung. When his doctor went to Mr. Watson’s house and measured levels of diacetyl in the air right after he made popcorn, they were found to be as high as those in a popcorn factory.
So should we all shun diacetyl-laced popcorn? Maybe, maybe not. As one report of the case put it, “There are no warnings from federal regulators, nor is there medical advice on how consumers” should treat the news. And that’s the quandary. The standards that the FDA, food industries and even physicians use for determining consumer safety do not always match the recommendations of scientists who study the health impacts of the multitude of chemicals we encounter.
No one knows how many chemicals with potential dangers lurk in the everyday objects we use and foods we eat. Informed estimates put the number of man-made chemical compounds floating about as high as 80,000 to 100,000. Of the ten thousand or so chemicals used in industrial amounts — yearly volumes greater than ten tons — only a fraction have ever been tested for toxicity in adults, let alone in fetuses or infants.
As for the potential harm from the chemicals in what we buy, use and own, many dangers are suspected but most all are “unproven,” in the sense of getting consensus on the verdict. Apart from a relatively small sub-class of chemicals, like concentrated doses of vaporized diacetyl, the chain of causality from chemical X to disease Y in most every case has yet to be investigated, let alone established.
In some cases science can identify certain ill effects from specific toxins and suggest a pathway consistent with those medical outcomes. But most of the apprehension centers on the simple fact that all synthetic chemicals are not natural elements in the body, and at a high enough level or in various combinations, their presence can do us harm.
Science cannot predict what specific effects these exposures will have in a given person; the body’s biological maze is simply too complex. Each industrial chemical engages our tissues in multiple ways. Some imitate the molecular structure of the body’s own hormones, ending up lodged in the endocrine system; others mimic the chemical messengers that keep cells in the brain and body working smoothly together. Some are readily absorbed in body fat, while still others – particularly the large number made from petroleum – readily slip through the oil-based membranes that surround cells (and these petroleum-based chemicals harbor carcinogenic benzene rings).
That’s one reason I love Environmental Working Group’s Skin Deep database: It levels the playing field.
Adapted from Ecological Intelligence: The Hidden Impacts of What We Buy. Originally posted at ewg.org