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Studies reveal traces in dust

Profile image for By Peggy Heinkel-Wolfe / Staff Writer
By Peggy Heinkel-Wolfe / Staff Writer

Chemicals linked to health problems found in household particulates

Two new studies published today could have you taking a closer look at the living room sofa and the dust on the mantel.

In the latest issue of Environmental Science and Technology, the two studies examine the presence of flame retardants in American homes.

Although researchers said the studies were not coordinated, one study found that sofas could be a significant source of flame retardant in house dust and another study found those same chemicals in house dust.

Mattresses use different flammability standards and are not likely to have flame retardants.

Researchers from Duke University and the University of California Berkeley tested foam samples from sofas around the country and found that most contained toxic flame retardants or flame retardants with unknown safety profiles.

In sofas, the two most frequently detected chemicals were chlorinated tris and PDBE, or polybrominated diphenyl ethers. Both chemicals have been linked to cancer and other health problems, the researchers said, and have already been banned in certain uses. Furniture makers phased out PDBE by 2004 after it was banned in the U.S. and Europe. Although chlorinated tris was banned from children’s sleepwear in 1977, furniture makers increased their use of it after phasing out PDBE.

University of California visiting scholar Arlene Blum, one of the study’s co-authors, said the use of flame retardants continues to be a complex, ever-shifting story for researchers, in part because there is little research to show that flame retardants are effective. Yet, manufacturers use a lot of flame retardant when making home furnishings. In a sofa, for example, the flame retardant makes up about 5 percent of the weight of the foam, Blum said.

“So if you have a large sofa, with 40 pounds of foam, 2 pounds of that is flame retardant,” Blum said.

The flame retardant releases chemicals into the air continually, and because those chemicals are heavy, they often end up in house dust, Blum said.

The concern over flame retardants began nearly 10 years ago when researchers from the Silent Spring Institute of Massachusetts found PDBE both in house dust and in people’s bloodstreams. After PDBE was phased out, the institute’s researchers tested house dust at a number of homes in low-income neighborhoods in two California cities in 2006.

In their newest study, Silent Spring researchers returned to the same California homes, now five years later. They tested for 55 target chemicals, including 49 flame retardants and 13 “legacy” chemicals such as DDT, which have been banned but are known to persist in the environment.

The results of that follow-up study were also published today in Environmental Science and Technology. Researchers found 41 of those 55 chemicals of concern — carcinogens, hormone disruptors and chemicals of unknown safety profiles — in the house dust, including PDBE, chlorinated tris and other flame retardants.

Their study focused on California homes because it was a California law that required furniture makers to meet flammability standards, according to the lead researcher, Robin E. Dodson.

“While we focused on California, we’ve found that its furniture standards essentially become a national standard,” said Dodson.

The chemical analysis cost about $500 per test for each home, she said.

Because labeling is not required, it is difficult for consumers to know what flame retardant may be in their draperies, carpets, sofas and other furniture. However, experts say if the furniture piece has a “Meets TB117” label — meaning that it meets California’s flammability standard — it nearly always contains flame retardants and, if made before 2004, PDBE.

Denton Fire Marshal Rick Jones said he was not surprised to learn that the retardant is ending up in house dust, since the instructions require the chemicals to be reapplied in order to be effective — but in some commercial settings, which may be worth the risk, he said.

However, the nature of house fires has changed. Because there are so many plastics in furnishings now, a “room-and-contents fire” does a lot more damage to the entire home than it did years ago, Jones said.

“When I first started my career in the 1980s, you still ran into cotton-batted and leather furnishings,” Jones said. Those fires didn’t fill the house with as much smoke as fast as they do today. Today, furnishings burn faster, hotter and produce more smoke — and the smoke is deadlier.”

That being said, he’s also seen evidence that treated materials can resist fire. In one recent house fire, for example, an elderly smoker got up from a chair and, distracted, dropped a cigarette in a blanket. While investigating the fire, Jones noticed that, in the parts of the chair that didn’t burn, there were several other cigarette burn marks where the retardant held. But if a cigarette falls between the cushions, or on a pillow or afghan, flame retardant in the foam isn’t going to help, Jones said.

Many of these products are the result of evolving problems, he said. Manufacturers started treating children’s sleepwear because of accidents with space heaters, for example.

The solution may mean more education, too.

“There’s not one fix for all problems,” Jones said.

If people want to reduce the presence of flame retardants, experts have several recommendations beyond buying naturally flame-resistant furnishings made with wool, cotton, polyester or down.

Controlling exposure to house dust may also help reduce exposure, experts say. People can reduce exposure through dust by washing their hands, mopping and dusting with a damp cloth and vacuuming with a machine equipped with a HEPA filter.

Instead of buying treated sleepwear for children, buy snug-fitting pajamas for children, which are less likely to catch fire, experts say.

PEGGY HEINKEL-WOLFE can be reached at 940-566-6881. Her e-mail address is