BELLEVUE, WA - While soils at some of the 34 child-use properties recently tested on Vashon and Maury Islands have averaged levels of arsenic and lead that are slightly above state cleanup standards, no immediate cleanup actions will be required, according to a study released today by the state Department of Ecology (Ecology) and Public Health — Seattle & King County.
The testing was conducted in fall 2000, in response to community requests, to analyze soil samples from areas where children visit or play on a regular basis. In 1999 and early 2000, Ecology and the local health department found widespread arsenic and lead soil contamination in undisturbed areas throughout Vashon and Maury islands.
Most of the soil contamination probably came from the copper smelter owned by Asarco that operated near Tacoma from 1890 to 1986. Contaminants from the smelter were spread by wind and deposited over Vashon and Maury islands as well as large parts of mainland King and Pierce counties. The area is called the Tacoma Smelter plume site.
Since children are considered to be at greatest risk for exposure to arsenic and lead, island property owners voluntarily allowed soil samples to be taken at 11 parks, 10 public and private schools, seven daycare centers, four campgrounds and two beaches.
"Over all, it is good news," said Dr. Ngozi Oleru, chief of the health department's environmental health division. "We found dramatically lower levels of arsenic and lead in the soil of developed playgrounds, parks, trails and yards than we found last year in the wooded areas on the island."
Although immediate cleanup actions are not required, Oleru said Public Health -Seattle & King Co., Ecology and the state Department of Health are advising all islanders to take general protection measures to keep exposure risks to a minimum.
"They can do things like covering any bare dirt in play areas, having everyone wash their hands when they come in from outside, and avoid letting anyone eat or drink outdoors in a contaminated area," she said. "It might even mean making everyone leave their shoes at the door. In general terms, people should avoid breathing or swallowing contaminated soil."
Under state law, the cleanup level for arsenic in residential soils is 20 parts per million (ppm). The cleanup standard for lead is 250 ppm. Before the results of study were known, Ecology and the local and state health departments adopted interim-action levels that are slightly above the state standard. The risk-based guidelines were developed to help determine which, if any, of the residential properties would require immediate cleanup action.
Since children spend longer, more regular periods of time clustered in schools and daycare centers, the interim-action level for these properties was set at 100 ppm for arsenic and 700 ppm for lead. The interim-action level for campgrounds, parks and beaches, where children spend less time, was 200 ppm for arsenic and 1,000 ppm for lead.
"None of the properties had averaged levels of contamination that reached those short-term action levels," said Ecology site manager Norm Peck. "Although at some properties, the averaged level of arsenic and lead was above the state cleanup standard, we felt most risks could be best addressed in the short-term by helping property owners put good, solid protection measures in place. These are common-sense steps that have been around for more than 20 years."
Peck said that properties with arsenic and lead concentrations above the state cleanup standard but below the interim action standard "are still of concern to us. They will need to be addressed as part of the long-term cleanup plan for the entire Tacoma Smelter plume site."
Other preliminary results of the soil sampling revealed that:
- The highest single concentration of arsenic found was 130 parts per million (ppm), compared to the state cleanup standard of 20 ppm. However, the averaged level of arsenic found was considerably lower - 4 to 50 ppm.
- The highest single concentration of lead discovered was 900 ppm (the state cleanup standard is 250 ppm). Again, the averaged level of lead was also considerably lower - 8 to 180 ppm.
- Some of the properties had multiple child-use areas, such as more than one playground.
- Four of the 34 child-use properties will need to be re-sampled because of high variability in the sampling results. For purposes of quality assurance to help the property owners get the best possible information, Public Health - Seattle & King Co. and Ecology will need to redo some sampling.
The two agencies will continue sampling to determine the extent of contamination on the two islands and mainland King County, and will evaluate other child-use areas for potential risks.
Ecology will also conduct a remedial investigation and feasibility study to develop a long-term cleanup action plan for the entire Tacoma Smelter plume site, which encompasses large portions of King and Pierce Counties.
Providing effective and innovative health and disease prevention services for over 1.8 million residents and visitors of King County, Public Health - Seattle & King County works for safer and healthier communities for everyone, every day.