PBDE Flame retardant found in Great Lakes Salmon

Margot Higgins / ENN 27feb01

More than 20 years after warnings about PCB contamination first surfaced in the Great Lakes region, concerns are heating up about the presence of another chemical in the same environment.

High levels of a common flame retardant found in plastics, foams and textiles has been detected in Lake Michigan salmon.

All 21 salmon examined in a recent University of Wisconsin study contained chemical compounds called polybrominated diphenyl ethers, or PBDEs, which are widely used for fire safety in computers, television sets, upholstery and cars. The average level of PBDE contamination in the salmon was 80 parts per billion — about six times higher than levels found in a 1999 salmon study in the Baltic Sea, where the most intensive research has been conducted for PBDEs.

"The concentrations are among the highest reported in the world for salmon in open waters," said Jon Manchester, lead author of the study. "We are concerned with any compound that bio-accumulates."

The findings present another reason to avoid eating salmon caught in the Great Lakes region.

"The discovery of yet another chemical contaminant in these salmon is another reason to observe the U.S.-Canadian International Joint Commission's recent recommendation that children and women of child-bearing age should avoid eating Great Lakes sport fish," said UW Sea Grant director Anders Andren.

The EPA ranks PCBs among the most toxic 10 percent of chemicals for human exposure. The agency notes, "PCBs do not biodegrade in the environment. They "weather but do not break down."

PCBs can travel great distances through the air. Health effects that the EPA has linked to PCBs include cancer, reproductive and developmental effects, immune deficiency, nervous system alterations, endocrine disruption, gastrointestinal system bleeding and liver damage.

While PCB production has been banned, PBDE output has been steady. Although restrictions exist in Europe, there are no proposals to limit PBDE use in the United States or Canada.

PBDEs and other brominated compounds are among the most effective and economical flame retardants on the market, accounting for about 25 percent of 600,000 tons of flame-retardant compounds produced worldwide each year.

The ongoing industrial production of PBDEs may create an environmental predicament similar to the problems caused by PCBs, environmentalists warn.

Studies indicate that, if ingested, PBDEs may increase the risk of cancer, liver damage and immune system dysfunction. Recent research on young mice showed that the chemical could create an adverse affect on neurodevelopment, learning, memory and reproduction.

Manchester hypothesizes that PBDEs may be even more persistent than PCBs in the environment. Although PBDE concentrations began to accumulate only about 20 years ago, they are increasing at a much more rapid rate than PCBs did, he adds.

Previous research in Scandinavia, Europe, Canada and Japan has detected PBDEs in sediments, meat, fish, sperm-whale blubber, office air and human blood, especially among workers in electronics recycling plants. A recent Swedish study found a 50-fold increase in PBDEs in women's breast milk between 1972 and 1997.

An upcoming three-year Sea Grant study will examine how PBDES enter the environment.