PORT ANGELES — Port Angeles, with its long history of mills, appears to have a higher level of dioxin in its soil than most communities, according to the state Department of Ecology.
Yet, residents should not worry, said Dr. Tom Locke, health officer for Clallam and Jefferson counties.
“As long as people don’t eat the dirt, the dirt is not dangerous to them,” he said.
A recently released study by Ecology traced the sources of dioxin, a carcinogen, in 85 samples taken in Port Angeles in fall 2008. The purpose was to determine how much of the contaminate may be the responsibility of Rayonier Inc.
Ecology is requiring Rayonier to clean up its former Port Angeles mill site.
The study traced the chemical to several sources, including chimneys, pesticides and hog fuel boilers used by mills, including Rayonier.
Forty of the 85 samples exceeded the cleanup level of 11 parts per trillion, an amount higher than levels found in other cities where similar studies have been done, said Connie Groven, environmental engineer with Ecology.
The dioxin produced by hog fuel boilers turned out to be a large contributor to those levels. Once taken away, the samples exceeding the cleanup level drop to 12 and resemble results found in other studies, Groven said.
What does it mean?
But those results deserve some context.
With a dioxin level of 11 parts per trillion, someone would have to consume 200 milligrams of contaminated soil every day for six years to develop a one-in-1-million risk of cancer, according to Ecology.
The samples were also taken from undisturbed soil in areas where people are less likely to be.
“If we wanted to look at risk, we would do the sampling in a different manner,” Groven said.
Locke said the highest risk of dioxin inhalation now comes from “backyard burn barrels” since industrial emissions are now “very tightly regulated.”
Dioxin emissions from Nippon Paper Industries USA’s mill aren’t expected to increase with its new biomass energy boiler even though it is planning to double its wood consumption.
Drop expected
Geoffrey Glass, Olympic Region Clean Air Agency engineer, said Nippon’s dioxin emissions are expected to change from between 3 and 3.5 milligrams per year to 3 milligrams with the new boiler.
Nippon Environmental Manager Paul Perlwitz said the new boiler will be more efficient and have better pollution control devices, so there won’t be an increase in dioxin emissions.
Nippon’s new boiler is expected to begin operating in late 2012.
Ecology staffers said they expect to require Rayonier to clean up dioxin outside of its mill site, though any action may be several years away.
Marian Abbett, Rayonier site cleanup manager, said additional samples may need to be taken before cleanup occurs.
Construction of the Port Townsend Paper Corp.’s biomass energy boiler is scheduled to begin later this year.
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Reporter Tom Callis can be reached at 360-417-3532 or at tom.callis@peninsuladailynews.com.