AT FIRST, the complaints weren't specific enough to cause undue worry: loss of energy, decreased appetite, acne, lowered libido. Managers at the manufacturing plant chalked up the workers' strange symptoms to their own sloppiness, "natural laziness," even "mob hysteria." Certainly, the company assured the public, the benefits of the chemical the workers were handling far outweighed any unproven, ambiguous health concerns.

Thirty years later, Swedish and American laboratory studies indicated a strong link between long-term health problems--including cancer--and the chemical the workers had been exposed to for decades. The chemical the workers at handled at the plant--and many other American plants just like it--was PCB (polychlorinated biphenyl), and its use in any form was banned by the U.S. government in 1976, half a century after it was first commercially produced.

PCBs loom as the kind of environmental horror story activists persist in reminding us about, because PCBs themselves persist, through bioaccumulation--levels of the chemical continue to show up in the body fat of animals and humans as part of what scientists term our "body burden" of toxics.

Environmental activists like to remind us about the horrors of PCBs because, they caution, it could happen again. In fact, they say, it might be happening right now, in Silicon Valley.

Up in Smoke

Polybrominated diphenyl ether (PBDE) started out as one of those brilliant inventions bound to save lives and make manufacturing easier. PBDEs are part of a family of chemicals called brominated fire retardants. Various forms of these chemicals are added to textiles, household and office appliances and upholstered furniture to inhibit their flammability. Without them, a match dropped on the couch could mean leaping flames instead of slow-moving smoke.

PBDEs are favored for fire prevention because they decompose at high temperatures and release bromine atoms, which interfere with the chemical reactions driving oxygen-dependent fires. Industry groups estimate that, in the case of a fire, flame-retardant treated products can ensure up to 15 times as much escape time as nontreated products.

It wasn't until recently, however, that scientists realized that PBDEs and other brominated fire retardants were decomposing at much lower temperatures than expected. A 1997 study from the Institute of Environmental Chemistry at the University of Stockholm, Sweden, discovered that flame retardants emit gasses between 86 and 104 degrees Fahrenheit, which is a common temperature inside a PC or TV that is turned on. The gasses are colorless and odorless. Once breathed in, they resist the body's efforts to break them down. Instead, like PCBs, PBDEs concentrate in lipids, or fat. They are highly resistant to physical, chemical or biological degradation.

In a study published this March, scientists at the California Department of Toxic Substances Control analyzed breast-fat tissue samples taken from women in the Bay Area in the 1960s and the 1990s. They found that there was a "significant increase" in the PBDE body burden of the samples taken in the 1990s--up to 40 to 60 times higher than levels found in Sweden.

If the chemicals stayed put in each human's body fat, the overall effect, while risky for that person, might not be so grave. But what concerns scientists and activists is that PBDEs have been found to be transferable through breast milk--and even to the tissue of fetuses.

Earlier this year, the European Union banned the use of PBDEs. However, North American industrial use accounted for half the world market in 1999. The technology industry embraced brominated fire retardants, and what is known as the "Deca" form of PBDE in particular, because it was easily mixed into polymers used in plastic computer housings, printed wiring boards and the insulation surrounding wire and cables and connectors. According to the Collaborative on Health and the Environment, PBDEs can "constitute quite a large percentage of the final product ... up to 30 percent."

While concern over PBDEs entering the environment through disposal of foam-upholstered furniture has recently been publicized, the fact is that more than 50 percent of industry use of PBDEs has been in the electronics and technology industry, according to the Environment California Research and Policy Center. And while California legislation to phase out certain types of PBDEs recently passed the legislature, spearheaded by Wilma Chan, the manufacturers of brominated fire retardants made sure the bill only regulated the types of PDBEs used in furniture foam and textiles, not the types most common in the electronics industry.

Health and Welfare

When PCBs were banned, in 1976, it was because they were found to suppress the immune system, alter brain development, lower the IQ and cause behavioral problems like attention deficit and hyperactivity in children. They were also eventually found to be cancerous agents and to alter sexual development. PBDEs are similar to PCBs in that they have been shown to affect fetal development.

While scientists like to be cautious in interpreting their data, lab research has shown that a body burden of flame retardants at the levels found in Bay Area women has the potential to disrupt the process of brain development in fetuses and infant children (through breast milk). It is tempting to relate this discovery to the increasing levels of autism, ADD and hyperactivity in Silicon Valley, although the causes of these disorders remain elusive.

A Swedish study published in 2001 by Eriksson, Jakobsson and Fredriksson showed that neonatal male mice exposed to even low levels of brominated flame retardants exhibited permanent behavioral changes, including erosion of "habituation capability" (the ability to adjust to environments), learning and memory.

The theory, advanced by yet another Swedish study, is that PBDE institutes these changes by interfering with thyroid hormone function. The chemical compound of PBDE mimics the natural hormone, binding with transthyretin, a protein crucial to normal thyroid hormone function. The thyroid is central to brain development.

There have been no long-term epidemiological studies on the effect of PBDE's hormone mimicry, but activists such as Ted Smith, executive director of the Silicon Valley Toxics Coalition, urge the maxim "better safe than sorry."

"We've got to take a cautionary approach which says the chemical companies have to prove these chemicals are safe, not wait for the long-term studies." Smith says. Some electronics companies that use PBDE are "already beginning to see the writing on the wall," he says. Hewlett-Packard and Apple have phased out use of PBDEs. "Unfortunately," Smith counters, "they haven't phased out use of another flame retardant--TBBPA."

TBBPA, or tetrabromobisphenol-A, is also chemically similar to PCB, is an endocrine disruptor, has also been found to leak from plastic and has been found in human blood tests to accumulate in the body. It is currently the preferred flame retardant worldwide in the electronics industry. It is not regulated, and there are no plans to regulate it.

Smith, who also heads the Take It Back Campaign to urge companies to accept back used equipment and recycle it properly, would like to see all flame retardants phased out. He says, "Our position is that they're all pretty bad, and it would be good to get rid of all of them so long as there are alternatives."

Metal Shop

What are the alternatives? Most of them involve doing away with plastic. Apple's Power Mac G4 desktop computer employs a metal chassis that would enclose any combustion, thus eliminating the need for flame retardants in the plastic housing. Hewlett Packard incorporated a metal chassis and power supply enclosure into its OfficeJet 500 printer so it didn't have to use flame retardants.

It seems like a simple solution: use things that don't catch on fire anyway, or use things that can contain flames, not chemically douse them.

Yes, great--but PBDEs and other fire retardants are already in the environment, and they're not going to go away. Without legislation to regulate them, they will continue to accumulate in our bodies and be passed on to our children, and the long-term effects will be finally understood via this global laboratory experiment.

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