Philadelphia Inquirer, Sandy Bauers
Published September 8, 2008
A common group of flame retardants used since the 1970s and credited with saving lives is proving to be a pervasive contaminant in the environment that may be harmful to human health.
The chemicals were added to textiles, couches, carpet pads, mattresses, and the hard plastics in TVs, computers, and other electronic devices.
Known as PBDEs, these organic compounds are now widespread in humans and the environment. They have been detected in breast milk and human blood, including umbilical-cord blood and livers of fetuses.
Health studies suggest that they may, at high levels of exposure, cause cancer.
Within the last year, studies have also found undescended testicles in babies whose mothers had high levels of PBDEs, decreased sperm quality in men, and effects on thyroid function.
The data are "young" and not definitive, said Linda Birnbaum, a senior Environmental Protection Agency toxicologist, who has studied the chemicals for several years. "But it is concerning."
PBDEs have been found in wildlife around the planet - from seals in the Arctic to eels in the Delaware River and bluefish caught off the coast of New Jersey.
Canada, Europe, and about a dozen states - but not Pennsylvania or New Jersey - have taken action to limit or ban the most common variations of the chemicals.
Ikea began phasing out the chemicals in 1998 and since 2002 has sold no furniture containing them.
In response to bans elsewhere, in 2004 U.S. manufacturers voluntarily ceased production of the version most often used in home furniture.
But researchers worry that older furniture or carpeting is still in use and may even be in some stores.
These products "have long lives in our homes," said Heather Stapleton, a Duke University environmental chemistry professor and PBDE expert.
Worse, consumers can't tell what kind of flame retardant the products they are buying contain. "No one is required to list" them, Stapleton said.
The Centers for Disease Control and Prevention has begun monitoring levels in humans as part of its National Health and Nutrition Examination Survey.
An EPA panel's latest status report, in March, showed it was continuing to assess risks and evaluate substitutes. It also is requiring manufacturers "to develop test data that will provide a better understanding of its fate in the environment," a spokeswoman said.
But the agency drew harsh criticism this year for dismissing Deborah Rice, the toxicologist who chaired the panel. An industry lobbyist had complained that she was biased. Critics called it another case of the agency caving in to business. The Inspector General's Office is investigating.
Industry spokesman John Kyte defended the chemicals as "very efficient, very effective flame retardants." He said well-financed activists with Internet savvy had unfairly "targeted" PBDEs - or polybrominated diphenyl ethers.
What complicates matters is that PBDEs, which are one group of brominated flame retardants, have 209 possible versions.
Concern has focused on two commercial variations, penta and deca, Latin words reflecting their atomic structures.
Penta was the type used in furniture, mainly in polyurethane foam common in mattresses, carpet pads and upholstery. In 2004, it was banned in Europe, and the sole U.S. manufacturer voluntarily withdrew it from the market. Ten states have also banned it.
The second form, deca, is still widely used in hard-plastic casings for televisions and other electronic equipment, even though many makers - including Apple, Dell and Hewlett-Packard - have decided to use alternatives.
Last year, both Washington state and Maine passed bills to phase out deca. This year, court action in Europe resulted in a ban, and Canada banned its production.
Deca is proving to have multiple lives.
Swedish researcher Ake Bergman, who several years ago termed PBDEs a "ticking time bomb," is alarmed to see deca making a reappearance in products that use recycled plastics.
Opponents want the industry to use substitutes for deca. "It's not that there aren't alternatives," industry spokesman Kyte said. "The sticky point is the alternatives have not been as well-tested and analyzed and don't have the track record of deca. Are we trading one perceived problem for something different?"
When researchers started measuring PBDEs in humans in the United States, they were amazed to find levels significantly higher than those in Europe. They concluded it probably had something to do with stricter flammability standards in this country.
Eventually they found the chemicals in household dust, which suggested an avenue of exposure. People get it on their hands, and put parts of their hands in their mouths.
To test the hypothesis, EPA researchers studied house cats, which sit on carpets and sofas and are continually grooming themselves. Sure enough, the cats had levels 10 times that of humans.
That put the focus on children, who also crawl on carpeting and put their hands in their mouths.
Another avenue for exposure is a car on a hot day. PBDEs have been used in seats and interior plastics.
Other potential problems: Although PBDEs are flame retardants, eventually they will burn. When they do, they could generate toxic vapors.
Meanwhile, researchers are discovering, to their chagrin, that PBDEs are ubiquitous in nature.
They have been found in California peregrine falcons, Puget Sound orca whales, and Greenland sled dogs. Among 33 species of Hudson River fish, PBDEs were found in 98.4 percent of the samples.
PBDEs have even shown up among invertebrates near Antarctica's McMurdo outfall, at levels near those in urbanized areas of North America.
Researchers surmised it was the result not of long-distance transport, but furnishings and electronics at research bases.
In the chemical's pervasiveness and persistence, researchers see disquieting parallels to lead in house paint and to PCBs - polychlorinated biphenyls - industrial chemicals banned 30 years ago but still common in the environment.
Similarly, with PBDEs, "we're looking at a very problematic chemical," said Bill Walker, vice president of the Environmental Working Group, an advocacy organization that wants them banned.
The group's work has concentrated on testing small samples of the human population to provide snapshots pointing to the need for further study. For instance, they obtained archived Red Cross samples of umbilical cord blood from 10 newborns, and tests showed PBDEs in every one of them.
On Thursday, the organization released the results of a study of 20 children, showing levels in their blood were triple those of their mothers.
In July, a new report on the health of the Delaware Estuary highlighted research funded by the estuary program, Pennsylvania Sea Grant, and the Academy of Natural Sciences that is just beginning to document PBDEs in the estuary.
Researcher Jeffrey Ashley, a Philadelphia University chemistry professor, figured that if PBDEs were present, they would surely show up in eels, which have fatty tissue where the chemicals would accumulate.
Looking at samples of 18 eels from six locations, PBDEs were in every one. Further, comparing PBDE levels to those found in other fish, "these were some of the highest."
Now, Ashley and colleagues are studying aquatic species at the John Heinz National Wildlife Refuge at Tinicum to map how the chemical accumulates as it moves up the food chain.
The marsh is where Delaware River fish are breeding and eating, and PBDEs are likely high. "When it rains, you can see the plastic bottles and condoms," he said. "What you can't see is the flush of contaminants."
