Dioxin questions rise along the Duwamish

The poisons surfaced first along the city streets, and later were found in yards and gardens, too.

For two years, residents of a small cluster of houses in Seattle's South Park neighborhood have known they were living with elevated levels of a toxic compound known as dioxin/furans. And for two years they've watched Seattle City Light and the federal government tussle over what to do about it.

Next month City Light and the Environmental Protection Agency plan to outline options for cleaning up one of the most polluted spots along the Duwamish River — the few blocks around an old asphalt plant not far from the South Park Bridge.

But those plans are expected to put off most decisions about dioxin, raising more questions in a neighborhood long frustrated by a lack of answers.

"They really don't have a good handle on it," said resident Tina Gary. "They were surprised to find dioxins there in the first place. Why should we be convinced they've got it figured out now?"

Dioxins are a byproduct of incineration and industrial activities involving chlorine, and collect in the fatty tissue of humans. People exposed to high levels can develop skin diseases, heart problems, diabetes and cancer.

Dioxin is found everywhere, but governments and industry have fought for 40 years over just how much low-level exposure is unsafe, leading to confusing guidelines between state and federal agencies.

The amount of dioxin found in the community of two dozen homes in 2008 is not overly high: about 20 to 50 parts per trillion. That's well-above levels at which the state urges cleanup, but well-below safety standards set by other agencies.

A State Department of Health study of the neighborhood is expected next month, though an early draft suggests health risks are extremely small, said health assessor Elmer Diaz.

But basic information is still hard to come by and frequently in dispute, including where the contamination originated, how widespread it is, and whether its volume exceeds what might be found in other neighborhoods.

The most obvious source might seem to be the asphalt plant, which operated from 1937 to 1993 and is known as a source of neighborhood contamination of polychlorinated biphenyls (PCBs).

The now-defunct company for years used waste oil from Seattle City Light for fuel, some of which it spread on streets to keep down dust. If the dioxin contamination gets linked to that fuel it would make the pollution Seattle City Light's responsibility.

But chemical fingerprinting has been inconclusive, and City Light has been unwilling to do more tests in the area.

The utility even has samples from the neighborhood in cold storage it has never analyzed for dioxin because it doesn't see a need.

"We're responsible for cleaning up areas our past practices connect us to," said Lynn Best, director of environmental affairs for City Light. "But at this point there doesn't seem to be anything that connects it (the dioxin)" to the asphalt plant.

The EPA, on the other hand, isn't ready to rule out the plant, and City Light, as a contributor.

"It's just not that clear-cut one way or another; we're still looking at the data," said Lori Cohen, associate director of EPA's Superfund cleanup program in Seattle. "I would say there is not absolute evidence one way or the other."

Meanwhile, EPA officials have said that dioxin data from Denver, Alabama and as far away as the Netherlands shows dioxin levels in this neighborhood are three to five times higher than what appears typical for most cities. City Light says there's too little data worldwide to reach that conclusion.

"We don't know what would be considered normal because so little testing has been done," Best said.

City Light maintains it wants to get to the bottom of the dioxin issue and is seeking grants to do in-depth regionwide testing.

But Best said ratepayers would be furious if City Light spent money cleaning up pollution it didn't cause or couldn't justify.

"We've been sued for that before," she said.

Certainly many residents understand her perspective. Lee Burnett has lived a few blocks from the asphalt plant off and on since 1939, and from his yard can see houses where people lived into their 90s despite pollution. He jokes about the holes surveyors poke in his yard trying to understand the contamination's spread.

But he recognizes that the science of dioxin's effect on people is complicated.

"I don't want to tell people who know more than I do what to do," Burnett said. "For all I know, some of these folks could have lived to 120 if they hadn't been surrounded by all this stuff."

But others are frustrated that the issue just drags on and on.

"Do I have dioxins in my yard? I don't know because they won't test it," Gary said. "We're all wondering what would happen if it were an area like Wallingford that had dioxin issues, what the city's response would be then."

Thea Levkovitz, with the Duwamish River Cleanup Coalition, an alliance of community groups trying to restore the waterway's health, said City Light should err on the side of this neighborhood.

"Let's be honest: None of the dioxin levels are screaming high," she said. "No one's going to die tomorrow. But these folks live where they have a lot of things going on, pollution from other sources, higher diabetes rates. They have to wipe their dogs' paws when they come inside. And we don't really know how much we don't know."

Craig Welch: 206-464-2093 or cwelch@seattletimes.com