New chemical alarm sounds

By Matt Crenson

Associated Press

A chemical flame retardant commonly used in foam furniture padding is accumulating so rapidly in the breast milk of nursing mothers that environmentalists and some scientists are calling for a ban on it.

Little is known about the toxic nature of polybrominated diphenyl ether, or PBDE. Early studies show it poses some of the same dangers as PCBs and DDT. Those two chemicals were banned in the United States decades ago due to their detrimental effects on the environment.

Environmentalists advocate a ban on polybrominated diphenyl ether as well. One form of the chemical will be banned next year in Europe, where the law requires proof of safety before a new agent can be used in the environment. U.S. law requires proof of harm or risk before a chemical is banned.

But the chemical industry argues that more research is needed before banning something that protects lives. Manufacturers say there is no evidence that the chemical reaches harmful levels in the environment, while its benefits as a flame retardant are well-known.

Adding the chemical to foam furniture padding, television casings and other plastics reduces the risk of death and injury due to fire by 45 percent, the chemical manufacturers say.

“We’re not talking about aesthetics. People use brominated flame retardants because they save lives,” said Robert Campbell, a spokesman for Great Lakes Chemical Corp. in West Lafayette, Ind.

Like PCBs and DDT, polybrominated diphenyl ether is a persistent organic pollutant that can remain in the environment for years without breaking down. Some of these pollutants have an affinity for fat and can build up in the bodies of animals and humans from before birth until death.

“It seems that PBDEs are an important – but generally unrecognized – persistent organic pollutant in the United States,” Robert Hale, a professor at the Virginia Institute of Marine Sciences, and five colleagues wrote in the journal Nature a few months ago.

Persistent organic pollutants are so difficult to purge from the environment that 25 years after being banned, trace amounts of PCBs can still be measured in human blood. Waterways such as New York’s Hudson River and Wisconsin’s Fox River are being dredged at costs running into the hundreds of millions of dollars to rid them of PCB contamination. In many waters, anglers are warned not to eat the fish or to limit their consumption to one or two servings a month.

“There is an enormous need to act quickly when there is a problem with a chemical that is not only toxic but is persistent and accumulates, because it will continue to get worse before it gets better,” said physician Gina Solomon, a senior scientist at the Natural Resources Defense Council.

Industry uses several forms of polybrominated diphenyl ether to decrease the flammability of plastics. Only one of those types – used mostly in polyurethane foam furniture padding – has been found in the environment and breast milk. According to Environmental Protection Agency records, Great Lakes Chemical is the only U.S. manufacturer of that form of the chemical.

“At this point, all bets are open in terms of how it’s getting into the environment,” said Hale, who stops short of calling for a ban on the chemical, which was developed in the 1960s.

He has hypothesized that discarded furniture is a major source of the chemical in the environment. Whenever anybody tosses out an old sofa, he said, nature goes to work. Water and sunlight break the foam into crumbling pieces that eventually are ground to dust. Insects also have been observed munching away at the material. From those humble beginnings, the chemical travels up the food chain to humans.

Hale has found polybrominated diphenyl ether virtually everywhere he has looked. In a small river along the North Carolina-Virginia border, he found fish with the highest levels of it ever recorded in any living creatures. He has also collected sewage sludge samples from four states, all with high concentrations of the chemical ether.

Swedish scientists first documented the increase of polybrominated diphenyl ether in humans. For 30 years, Sweden has sampled the breast milk of nursing mothers to track exposure to dioxin, PCBs and other pollutants that accumulate in body fat. The United States has no similar program.

In 1998, Swedish scientists reported that levels of the chemical in breast milk had increased fortyfold since 1972.

Since the Swedish discovery, the chemical has been found in Swedish pike, Virginia catfish and North Sea cod. Seals, moose and reindeer all carry it in their body fat and, like humans, transmit it to their nursing young. It has even been found in the blubber of sperm whales in the Arctic Ocean.

Even more alarming to environmentalists was the revelation in December by the journal Environmental Science &Technology that North American mothers have breast milk levels of the chemical at least 40 times greater than the highest concentrations found in Sweden.

“It’s humongously high,” said Mehran Alaee, a Canadian government scientist who compiled the North American data. “If you let it go like this, it will reach a point sooner or later that it will cause some damage to the environment.”

Where that point lies, nobody knows. Researchers simply have not collected the information they need to determine how much of the chemical is harmful.

“What we have seen in our developmental neurotoxicity studies … is that PBDEs can be as toxic as the PCBs,” said Per Eriksson, a toxicologist at Uppsala University in Sweden.

Eriksson’s experiments have shown that one large dose of the chemical delivered early in a mouse’s life can cause permanent brain damage. Similar experiments by Per Ola Darnerud of Sweden’s National Food Administration have determined that in mice, the smallest dose of the chemical that can cause observable health effects is about 1 million times greater than current human exposures.

But those experiments both involve relatively large amounts given to animals over a short time. Nobody really knows how lower doses delivered over decades affect humans.

“I’m hoping that within two to three years we’ll have an answer,” said Kevin Crofton, a toxicologist with the Environmental Protection Agency’s National Health and Environmental Effects Research Laboratory.

Faced with similar uncertainty in May 2000, the 3M Co. chose to remove a similar persistent organic pollutant from Scotchgard and several other products.

Users of the chemical could do the same, substituting another flame-retardant chemical in its place. But it has properties other flame retardants don’t have, Campbell said. It does not discolor foam or decrease its durability as much as other flame retardants. And though all flame retardants evaporate into room air in trace amounts, polybrominated diphenyl ether does so at lower levels compared to many alternatives.

For that reason, Great Lakes Chemical has chosen to continue producing its polybrominated diphenyl ether products for the time being.

“If things turn out that the levels that are going to get into the environment are problematic, we’ll do the right thing,” Campbell said.

In Europe, environmental authorities have already decided that the chemical warrants action. Beginning next year, the variety that has shown up in breast milk will be banned.