MedlinePlus Medical Encyclopedia: Lead levels

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Lead levels - blood

Contents of this page:
Illustrations Alternative names Definition How the test is performed How to prepare for the test How the test will feel	Why the test is performed Normal Values What abnormal results mean What the risks are Special considerations

Illustrations

Blood test

Alternative names Return to top

Blood lead levels

Definition Return to top

This is a test that measures the amount of lead in the blood.

How the test is performed Return to top

Blood is drawn from a vein, usually on the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and an elastic band is placed around the upper arm to apply pressure and restrict blood flow through the vein. This causes veins below the band to fill with blood.

A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. During the procedure, the band is removed to restore circulation. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

The blood is collected and transported in containers that do not contain lead. It is usually evaluated by atomic absorption spectroscopy.

How to prepare for the test Return to top

No dietary restriction of food or fluid is necessary.

If your child is to have this test performed it may be helpful to explain how the test will feel, and even practice or demonstrate on a doll. The more familiar your child is with what will happen to them, and the purpose for the procedure, the less anxiety they will feel.

How the test will feel Return to top

When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

Why the test is performed Return to top

While lead serves no function in our bodies, it is usually present to some degree since it is so common in our environment. Low levels in adults are not thought to be harmful, but in infants and children, low levels of lead can lead to toxicity (see lead poisoning) such as deficits in intellectual/cognitive development.

This test is performed to screen people at risk for lead poisoning (such as industrial workers or children in urban areas), and to monitor the improvement of those who already have diagnosed increased serum lead levels, or lead toxicity.

Normal Values Return to top

Adults:

less than 20 micrograms/dL of lead in the blood

Children:

less than 10 micrograms/dL of lead in the blood

Note: dL = deciliter

What abnormal results mean Return to top

Adults:

greater than 30 micrograms/dL of lead in the blood

Children:

greater than 10 micrograms/dL of lead in the blood is abnormal and may be associated with intellectual deficits
greater than 25 micrograms/dL of lead may indicate the need for treatment with a chelation agent such as calcium disodium edetate

If you have elevated lead levels, it is vital that you are separated immediately from the source of the lead. You should discuss possible sources of exposure and ways to eliminate the exposures with your health care provider.

Note: dL = deciliter

What the risks are Return to top

Risks associated with having blood drawn are slight:

excessive bleeding
fainting or feeling light-headed
hematoma (blood accumulating under the skin)
infection (a slight risk any time the skin is broken)
multiple punctures to locate veins

Special considerations Return to top

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Update Date: 9/3/2003

Updated by: Michael C. Milone, M.D., Ph.D., Department of Pathology and Laboratory Medicine, University of Pennsylvania Medical Center, Philadelphia, PA. Review provided by VeriMed Healthcare Network.

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