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December 2004 Update
This update provides the latest results from the
Extended Footprint Study.
Introduction
Footprint Studies
Child-Use Area Studies
Resources: Simple
Steps to Protect Your Health
Local Health Department Web
Links
Introduction
Since 1999, the Department of Ecology (Ecology) and the King and Pierce County
health departments have been studying soil pollution that came from the
Asarco Smelter smokestack. The polluted smoke that came out of the
smokestack traveled with the wind and settled onto soil in much of the
southeastern Puget Sound Basin.
The agencies have studied:
Study results show that contamination is widespread but there is no human
health emergency. Local health departments and the State Department of
Health have determined that the lead and arsenic are of concern, and an
informed community is important to protecting human health. Local health
departments and Ecology are providing information to people about the
contamination and what they can do to protect their health.
Footprint Studies
Initial Footprint Studies
To get an overall view of the general “footprint” of contamination, three
initial soil sampling studies were done:
Vashon Island,
Mainland King County
and Pierce
County. These footprint studies were designed to find the highest levels
of contamination in each area. Soil samples were collected from properties
with the least disturbance, such as undeveloped forests, because soil
disturbance during construction, farming and other activities may dilute
surface contamination. Study results show higher than normal levels of
arsenic and lead in the surface soil (usually the upper six inches) in some
locations.
Extended Footprint Study
[The maps in this section are in Adobe Acrobat (.pdf) files, zoom in to better see map details*.]
The initial studies did not identify the polluted area’s boundary. To find out how far the soil pollution extends, Ecology teamed up with the King, Kitsap, Pierce and Thurston County health departments to conduct a final study - the Extended Footprint Study. Ecology provided grants to the four counties to conduct this work.
As of December 2004, sampling was completed in all four counties. The results appear consistent with the pattern of contamination seen in the initial studies. In general, the concentrations of arsenic and lead decrease with distance from the smelter and follow wind patterns. We believe we have sufficient information to determine the general boundary of the contamination.
The total area potentially impacted by smelter emissions appears to be 1000 square miles. The maximum concentrations at each sampling location are mapped for Arsenic and Lead.
Investigators collected soil samples from 51 undisturbed locations in northeastern Thurston County. Nineteen locations had arsenic levels above the state cleanup level of 20 ppm, and one had lead levels above the state cleanup level of 250 ppm.
Among these soil samples, Thurston County has an area of interest with more soil contamination than anticipated. In the highland area on top of the Nisqually Bluff, arsenic values topped out at 159 parts per million (ppm) and lead values at 1100 ppm.
The results seem to reflect the wind channeling down the Sound, hitting the bluff. However, the arsenic and lead ratios do not fit the normal Tacoma Smelter Plume pattern. There may be an additional source. Thurston County Health is investigating further.
The Thurston County Health Department has been in contact with property
owners in the area and will continue to work with them. They are
providing educational materials to area childcares for protection of kids
and employees, in addition to advising all of Thurston County to follow
public health
protection measures such as washing dirty hands, and taking off shoes to
avoid tracking in dirt.
Thurston County Maximum Arsenic
Thurston County Maximum Lead
Researchers collected soil samples throughout the county from the foothills
west to the Puget Sound. Of the 165 new results reported by Public
Health-Seattle & King County, 65 locations have arsenic above the state
cleanup standard, and one location had lead above the standard. The highest
arsenic and lead concentrations were 77 ppm and 311 respectively. The
highest arsenic concentration found in previous studies was 460 ppm on south
Vashon-Maury Island.
King County Maximum Arsenic
King County Maximum Lead
In Pierce County, soil samples were collected south and east of I-5,
including areas near Roy and McKenna. Of the 84 new locations sampled, 18
had arsenic levels above the standard, and 12 had lead levels above the
standard. The highest arsenic and lead concentrations were 352 ppm and 1940
ppm respectively. Previous studies found arsenic levels as high as 1050 ppm
in Tacoma.
Pierce County Maximum Arsenic
Pierce County Maximum Lead
In Kitsap County, soil samples were collected along the Puget Sound coast
line in eastern parts of the county. Of 53 locations sampled, 13 had arsenic
levels above the standard, and no locations had lead above the standard. The
highest arsenic and lead concentrations were 37 ppm and 198 ppm
respectively.
Kitsap County Maximum Arsenic
Kitsap County Maximum Lead
We expect a report in spring 2005 that will summarize results from the initial
and final studies, and includes a determination of the boundary of
contamination.
Child-Use Area Studies
In addition to studying how far the pollution went, Ecology and the health
departments in King and Pierce counties have studied the soils where
children play – schools, parks, childcares. We are concerned about long-term
exposure to the contaminated soil, especially for young children as they
face the highest risk from soil contamination. Children like to play in the
dirt. Very young children place dirty fingers and objects in their mouths,
and they are more likely than adults to accidentally eat soil. Children are
the most vulnerable to health effects from contaminated soil because their
bodies are still developing.
Three studies have been completed in child-use areas:
Vashon Island,
Mainland
King County, and
Pierce County. For
the most part, average concentrations of arsenic and lead in the surface
soils are below the state cleanup levels. For those child-use areas with
arsenic or lead above the state cleanup level, Ecology and the health
departments recommend following the soil safety guidelines provided by the
health departments. These are called
Soil Safety Guidelines in King County and
Healthy Actions in Pierce County.
Examples of the guidelines include:
The effectiveness of these measures depends upon their consistent use.
While nearly 100 child-use areas were sampled in coastal King County in
2003, there are many more that have not been sampled. As part of the grant
provided by Ecology, Public Health - Seattle & King County plans to offer
sampling to additional child use areas. Public Health will begin
collecting soil samples in early 2005, completing the study by June
2005.
Resources: Simple
Steps to Protect Your Health
There are some simple steps you can take to protect you and your family’s
health, and to better understand how the smelter has affected your local
community. Ecology and our health department partners encourage you to check
out soil sampling and safety brochures.
Local Health Department Web Links:
King County: http://www.metrokc.gov/health/tsp/arseniclead.htm
Pierce County: http://www.tpchd.org
Thurston County: http://www.co.thurston.wa.us/health/ehtsp/index.html
Kitsap County: http://www.kitsapcountyhealth.com/tacoma_smelter_project.htm
*A free version of Adobe Acrobat can be
downloaded by clicking on the "Adobe Reader" link at left.
Copyright © Washington State Department of Ecology. See http://www.ecy.wa.gov/copyright.html.
