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Toxics Cleanup Program

Areawide Soil Contamination Project

Toolbox Chapter 4

What is Known about Health Risks from Exposure to Low-to-Moderate Levels of Arsenic and Lead in Soil?

The risk of developing health problems from arsenic or lead depends on the amount of exposure and the concentrations to which a person is exposed.  The greater the exposure or the greater the concentrations, the greater the risk.  Most information about the health effects of arsenic and lead comes from studies where exposures were greater than those expected from living and working in places with low-to-moderate levels of arsenic and lead in soil.  Health monitoring and research studies have not been carried out to the extent necessary to understand and document whether exposure to low-to-moderate level arsenic and lead in soil is causing or contributing to long-term health problems in Washington.   

Evaluating health effects at lower levels of exposure is difficult, and it is unlikely that conclusive scientific information to determine the health risks from exposure to area-wide soil contamination will be available in the foreseeable future.  In light of this uncertainty, there is disagreement among scientists about how the information that is available should be interpreted and used to assess the risks of exposure to low to moderate level soil contamination.  Some members of the scientific community argue that federal and state efforts to address low to moderate level soil contamination are not scientifically justified because there is no information demonstrating that health problems are being caused by exposure to such contamination.  Other members of the scientific community argue that arsenic and lead in soil have the potential to cause health problems at low levels of exposure—especially for people who are particularly sensitive to the effects of these contaminants.  In recent years, the majority of scientific review committees formed to evaluate the available scientific information on arsenic and lead have concluded that there is a sufficient scientific basis to justify efforts to reduce exposure to these contaminants.

What are Health Risks from Exposure to High Levels of Arsenic and Lead?

Exposure to high levels of arsenic and lead can cause health problems in people.  Arsenic can cause more than 30 distinct health effects, including nervous system damage, increased blood pressure, heart attack, stroke, and cancer of the bladder, lung, skin, and other organs.  Lead can affect many parts of the body, causing health effects that include increased blood pressure, kidney damage, and brain damage.  Although both children and adults can be adversely affected by lead poisoning, it is a particular concern for young children.  Arsenic and lead are both considered persistent contaminants.  This means that they bind strongly to soil and usually remain in the environment without breaking down or losing their toxicity, and thus can be a source of exposure for many decades. 

How to Obtain Blood Lead Level Tests for Your Children

Children ages six and younger are at much higher risk of lead poisoning.  Parents who wish to have their children tested for lead should contact a pediatrician or health care provider.  For more information, please visit the Washington State Department of Health Childhood Lead Poisoning Prevention Program’s website at:

The Washington State Department of Health Lead Information Hotline can be reached at 1-800-909-9898.