Chemical sneaks into Great Lakes

[GLF]

It predated test rules; threat is unclear

A little-studied fire retardant has accumulated in Great Lakes sediment and game fish for decades without detection, according to new research.

The discovery about Dechlorane Plus, which went into production in 1964, surprised federal regulators.

"If this was a brand-new chemical, it would probably never get through" the testing process to allow its commercial use, Linda Birnbaum, a leading U.S. Environmental Protection Agency expert on toxic chemical effects, told the journal Environmental Science & Technology for a Jan. 4 article about the study.

But it is unclear what, if any, threat there is to human health or the environment from Dechlorane Plus, used for more than 40 years as a coating for electrical wires and computer cables. The chemical's only U.S. manufacturer, Occidental Chemical Corp. (OxyChem) says it is safe for people and other animals and has no plans to conduct testing on the product, which is manufactured at a plant in Niagara Falls, N.Y.

The study found Dechlorane Plus in the sediment of lakes Erie and Michigan, present in air samples throughout the region and in the tissues of walleye, a popular game fish, in Lake Erie, according to research by scientists at the Indiana University School of Public Health and Environmental Affairs.

For decades, state officials have issued advisories to anglers to limit their consumption of some Great Lakes fish because of contaminants such as PCBs and mercury. The greatest risk from pollutants in the water is, by far, eating game fish from them. The chemicals become increasingly concentrated as they move through the food chain from microscopic plants and animals to small fish to bigger fish to humans.

Federal regulators say because Dechlorane Plus preceded regulations designed to screen out dangerous chemicals, it was never rigorously tested.

"This is an example of a relatively old compound that has apparently slipped under the regulatory radar and that is still currently being used without attracting public attention," wrote Ronald Hites, one of the Indiana researchers who discovered the chemical in the ecosystem. "This compound has not been detected in the environment before."

The study could lead to a renewed effort to determine whether it is a danger to wildlife, including its potential to cause cancer. Many substances in the same chemical family -- including the insecticides aldrin, dieldrin and mirex, which was sold under the brand name Dechlorane -- have been banned because of their cancer-causing potential and toxicity to wildlife.

Mirex/Dechlorane was manufactured at the same facility, which was formerly known as the Hooker Chemical Co., responsible for the Love Canal chemical disaster in Niagara Falls in the late 1970s that spawned the federal Superfund toxic cleanup program.

Birnbaum of the EPA said the chemical similarities between the banned Dechlorane and Dechlorane Plus should require further scrutiny of the latter.

"From a toxicity standpoint, when you have one that looks so much like another, it's something you need to look at," she said Thursday. But she added that even tiny changes to a chemical's structure can make significant differences in its toxicity.

Dallas-based OxyChem says Dechlorane Plus is not a concern.

"OxyChem would not sell the product if we did not believe it could be used safely," Larry Meriage, a company vice president, said in an e-mail response to questions. The chemical's molecules are "large and not easily absorbed by animals or aquatic organisms," he said.

Meriage said OxyChem has hired a toxicologist to respond to questions about Dechlorane Plus from the EPA. The EPA's questions are part of a voluntary testing program created by industry and the federal government to keep tabs on chemicals produced in large quantities.

Data from that program indicate that it appears to have toxic effects on fish and may affect rabbit reproduction when applied to the animals' skin.

And that data is incomplete, the EPA told the company in an August letter.

The EPA cited incomplete data regarding how quickly the chemical degrades and how it affects animals exposed to low doses over long periods. The EPA said "no adequate data were submitted" for the ecological effects of Dechlorane Plus, although it said that was not necessary because the properties of the chemical "suggest that measurable toxicity to aquatic organisms will not occur."

Some scientists say the chemical may not be a serious health threat because of its structure. "It would have a tough time passing past your gut wall and into your bloodstream," said Heather Stapleton, an assistant professor of environmental chemistry at Duke University in North Carolina. "But certainly further study is needed. There is always the possibility it could break down into" more readily absorbed compounds, she said.