News Coverage
Playfront's arsenic levels elevated;
Published September 26, 2002
Like most structures built with pressure-treated wood, the playground at Duluth's Bayfront Festival Park has arsenic in it.
Its levels of the cancer-causing poison are slightly elevated, but not alarmingly so, a state health official said Thursday, reacting to the results of an independent environmental analysis commissioned by the News Tribune.
The analysis of arsenic levels is the first done at Playfront.
"The levels you found don't indicate a great risk," said Carl Herbrandson, a toxicologist for the Minnesota Department of Health in the Twin Cities. "There are other sources of arsenic that are much higher that you'll come across in your everyday life, like food or water. On the other hand, we don't like to see arsenic levels elevated ever. And these levels do appear to be slightly elevated." This spring, as part of planning for the Bayfront, city officials talked about replacing the wooden playground, citing arsenic in the wood as one reason. More questions surfaced this month when volunteers turned out to help sand the structure as part of a maintenance effort.
Soil samples taken andanalyzed by Arrowhead Consulting and Testing of Duluth found levels of arsenic six inches from the playground at 30 ppm (parts per million) and at 22 ppm one foot from it. Both samples were taken between the surface and 6 inches deep.
To put those numbers into perspective, Herbrandson said typical soils in Minnesota have a natural arsenic level of about 6 ppm. An acceptable level for a residential neighborhood, according to the state health department, is about10 ppm. But he has seen natural levels as high as 22 ppm, he said.
"I would be much more concerned about infants crawling on untreated decks or the improper disposal of arsenic-treated wood," Herbrandson said.
A surface dust sample wiped from a square-foot area of the wooden play equipment found an arsenic level of 8.8 micrograms per square foot. That's the amount that can be transferred to children's hands during play.
It's also the typical level found on many play sets, decks and picnic tables built with so-called green-treated lumber, or lumber treated to prevent deterioration with chromated copper arsenate, Herbrandson said.
But one sample from the surface of a play set cannot be considered indicative of the entire structure, he said.
"To come up with an actual arsenic exposure rate from all of this is difficult," Herbrandson said. "We do like to see arsenic exposure kept to a minimum, obviously."
The News Tribune commissioned the tests from Arrowhead Consulting and Testing on Sept. 19, four days after volunteers, city officials and members of the Junior League of Duluth together sanded the playground. In 1990, league members organized a volunteer effort to build the playground. This fall, they're working to improve and reseal the structure.
An environmental researcher in Washington, D.C., concurred Thursday that the levels of arsenic in the playground aren't unusual.
"That's relatively low," Sean Gray of the Environmental Working Group said of the wood-surface sample. "A lot of the arsenic that was probably on the surface no doubt ended up on the ground because of the sanding. That's probably why the soil samples are relatively high."
On Oct. 12-13, Junior League members will call on volunteers again to remove pea gravel and wood chips on the ground around the play area and replace them with clean sand. That should help reduce the in-soil arsenic number.
"It's nice to hear your town is taking steps to address all of this," Gray said. "Because those soil levels now really are a concern. You don't want your children eating that soil.
"But for a structure 10 or so years old," he said of Playfront, "the numbers indicate a normal profile based on what we found across the country."
Gray's nonprofit environmental advocacy and watchdog group tested several hundred wood decks and play sets in 45 states. Its findings on arsenic levels were analyzed by the Environmental Quality Institute at the University of North Carolina-Asheville and released last month.
A day after Arrowhead Consulting and Testing owner Linda Thiry collected samples from Playfront, the city of Duluth ordered its own tests. City officials hired Twin Ports Testing to measure arsenic, copper and chromium levels in three soil samples around the playground.
The tests will cost the city between $500 and $600, said Dick Larson, director of Public Works and Utilities. Results are expected within days.
"It's more a matter of information, for our own information. There are no legal or regulatory reasons why we're doing it," Larson said. "There's just been a lot of discussion. I just thought it would be good to find out.
"If we find levels above the recognized standards, then we need to deal with it," he said. "But if we find levels below the standards, then maybe we can put this thing to bed once and for all. We'll react to the results when we get them."