- A group of flame retardants called HBCD are fat-soluble and appear in a wide variety of fatty foods.
- Studies show that flame retardant chemicals don't actually reduce flammability in many furniture foams.
- It can take years for flame retardants to break down in the body and we are all constantly being exposed.
A common flame retardant showed up in a variety of store-bought foods including meat, peanut butter and fish.
The discovery of the chemical HBCD adds to growing evidence that our food supply is full of unwanted chemicals, including flame retardants. The study also draws yet more attention to growing concerns about a ubiquitous class of poorly regulated chemicals that, according to growing evidence, may be harmful to our health, the environment and wildlife. Despite all the potential risks, flame retardants are also possibly ineffective at resisting fires in many situations.
"What we're seeing are chemicals that can cause endocrine disruption, that can cause nervous system damage, that can cause reproductive damage, that can cause developmental damage, that can cause cancer in some cases," said Arnold Schecter, a public health physician at the University of Texas School of Public Health in Dallas, who has been systematically uncovering a wide range of chemicals in supermarket foods. "To me, what I see as the big picture is the fact that, now that we're looking, we're finding them in many of the foods we're looking at -- not all of them, but in large numbers of them."
HBCDs are a group of brominated flame retardants that appear frequently in home insulation materials. They are more common in Europe than in the U.S, but in previous work, Schecter found the chemical in the breast milk of American women as well as in various foods sold here.
There are dozens of chemicals that manufacturers use to try to reduce the flammability of all sorts of products, including furniture, electronics, baby car seats and carpets. Based on their chemical structures, flame retardants can fit into one of several categories, and some categories have raised more health concerns than others.
So far, two classes of flame retardants -- brominated and chlorinated -- have sparked the most worry, Schecter said, partly because they accumulate in human tissues and partly because they last for a really long time. After exposure, the human body can take up to 219 days to break down just half of a dose of some of the most persistent versions.
Recent studies suggest that we are constantly exposed to a variety of flame-retardants. House dust is full of the chemicals, which easily leach out of treated foam in furniture and other household objects. Studies have found these chemicals in animals as well as in human blood, urine and breast milk. One group of flame retardants called PBDEs, which are commonly used in the United States, appear in breast milk at higher levels in America than they do in Europe, where PBDEs are being phased out.
To get a more detailed picture of which forms of HBCDs show up most often in our food supply and which foods carry the highest loads, he and colleagues bought 36 types of food from Dallas supermarkets. They picked foods that had tested positive in their previous work, including fish, turkey, peanut butter, bacon, and beef. The list was heavy on fat-containing foods because HBCDs are fat-soluble.
In the new study, levels turned out to be highest in canned sardines, fresh salmon, peanut butter and tilapia, the researchers report today in the journal Environmental Health Perspectives. Other foods that tested positive at lower amounts included canned chili and sliced ham, turkey, chicken and other deli meats.
Individually, none of the foods had high enough levels of HBCDs to be of concern. But that doesn't necessarily mean there's nothing to worry about.
"The levels are lower than levels that any government agency that we know of has suggested as a do-not-exceed or dangerous or reference dose -- that's the good news," Schecter said. "The thing that isn't good news is that we are finding so many different toxic chemicals in food."
"What concerns me is that the limits that are recommended not to be exceeded that government agencies put out are usually reviewed one at a time from animal studies or cell culture studies or human epidemiological studies," he added. "I don't think we have a good feel for what the toxicity is of these mixtures of chemicals found in our food and in our bodies."
The new findings are useful, considering we know relatively little about HBCDs, said Heather Stapleton, an environmental chemist at Duke University in Durham, N.C.
It's impossible to completely avoid flame retardants, she said. But to reduce chemical exposures, she recommended frequent hand-washing. She also suggested that consumers call manufacturers and ask them to provide more information about what chemicals they use in their products.
"We know these accumulate in house dust, and now it seems another route of exposure is in food," Stapleton said. "There's just so much we don't know."