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Public Health - Seattle & King County

Information about lead and arsenic

Lead in Washington state soil

The Washington State Department of Ecology and the United States Geological Survey have determined that the natural background level of lead in Puget Sound soil is 24 ppm (parts per million). The state average is 17 ppm. More information on the study that determined these levels.

Lead pollution

Washington law requires that soils contaminated with lead above the state clean up level be cleaned up. These levels vary depending on the use of the property. For residential sites, regulations require that soil be cleaned up to 250 parts per million (ppm).

Ecology regulates soil contamination under the Model Toxics Control Act (MCTA). Read more about MCTA.

The Tacoma Smelter Plume represents soil contamination on a very wide scale. Therefore, Ecology has developed special plans to address this contamination and other "area wide" contamination in Washington State. Learn more from the Ecology Area Wide Web site.

Lead and your health

Lead is toxic to human beings and children are particularly sensitive to its effects. Children, especially toddlers, are at highest risk for lead poisoning. Ingesting (eating) lead – whether it is in the soil, in paint chips, or from any other source - is a serious health risk and can result in both short and long-term health problems.

Acute (short-term) exposure to high levels of lead can result in brain and kidney damage. Chronic (long-term) exposure may affect the blood and central nervous systems, blood pressure, kidneys and the body's ability to metabolize (use) vitamin D. Lead exposure may damage the reproductive system, resulting in reduced sperm counts and increased miscarriage.

Newborns and young children under six are particularly vulnerable to the effects of chronic lead poisoning. Effects range from lowered IQ (intelligence) and reduced growth to balance, memory, and hearing problems. Pregnant women exposed to lead may have babies born prematurely and at lowered birth weights. The blood brain barrier, which keeps toxins out of the body, is not fully developed until about age six. Learn more about the blood brain barrier at Neuroscience for Kids.

Since children are especially sensitive to lead, doctors may prescribe blood tests to screen them for possible long-term lead exposure. If you suspect you or your family has been exposed to lead, discuss it with your doctor or pediatrician. A blood test can measure blood lead levels.

Additional information about lead:

Arsenic in Washington state soil

Arsenic is a naturally occurring substance, and occurs in inorganic and organic states. Organic arsenic, which is relatively less toxic, occurs naturally in plants, fish, and shellfish. Inorganic arsenic - arsenic combined with oxygen, chlorine or sulfur - is the most toxic. The Asarco arsenic is primarily inorganic.

In Washington, arsenic occurs naturally in the soil. The Washington State Department of Ecology and the United States Geological Survey have determined that the natural background level of arsenic in Puget Sound soil is 7 ppm (parts per million). For more information on the study that determined these background levels consult the Ecology publication: "Natural Background Soils Metals Concentrations in Washington State" Publication #94-115.

Arsenic pollution

Washington law typically requires that soils contaminated with arsenic above the state clean up level be cleaned up. These levels vary depending on the use of the property. For residential sites, regulations require that soil be cleaned up to 20 parts per million. Ecology regulates soil contamination under the Model Toxics Control Act (MCTA). Read more about MCTA.

The Tacoma Smelter Plume represents soil contamination on a very wide scale. Therefore, Ecology has developed special plans to address this contamination and other "area wide" contamination in Washington State. Learn more from the Ecology Area Wide website.

Arsenic and your health

Arsenic is extremely poisonous. Even so, it has numerous industrial uses and has been used widely. For example, it has been used in insecticides such as Paris Green, calcium arsenate and lead arsenate. Arsenic is well known from former use as a rat poison.

Arsenic has a long history of medical applications. For example, before penicillin was developed an arsenic compound was used to treat syphilis and yaws (frambesia). Other uses of arsenic include ammunition manufacturing (because it helps to create harder and rounder bullets), semi-conductor manufacturing, and as a preservative in tanning, taxidermy, and wooden deck and playground materials.

Arsenic can cause both acute and long-term health effects. One of the problems with arsenic exposure is that many of the symptoms may result from causes other than arsenic - so a person who has been exposed may not suspect arsenic.

Acute (short-term) arsenic poisoning may cause nausea, vomiting, diarrhea, weakness, loss of appetite, shaking, cough and headache. Chronic (long-term) exposure may lead to a variety of symptoms including skin pigmentation, numbness, cardiovascular disease, diabetes, and vascular disease. Long term exposure to small amounts of arsenic is also known to cause a variety of cancers including skin cancer (non-melanoma type), kidney, bladder, lung, prostate and liver cancer.

Additional information about arsenic: