Blood lead level is a test that measures the amount of lead in the blood.
Blood lead levels
How the test is performed
A blood sample is needed. Most of the time blood is typically drawn from a vein located on the inside of the elbow or the back of the hand.
In infants or young children, a sharp tool called a lancet may be used to puncture the skin.
The blood collects in a small glass tube called a pipette, or onto a slide or test strip.
A bandage is put over the spot to stop any bleeding.
How to prepare for the test
No special preparation is needed.
For children, it may be helpful to explain how the test will feel and why it is done. This may make the child feel less nervous.
How the test will feel
You may feel slight pain or a sting when the needle is inserted. You may also feel some throbbing at the site after the blood is drawn.
Why the test is performed
This test is used to screen people at risk for lead poisoning. This may include industrial workers and children who live in urban areas. The test is also used to measure how well treatment for lead poisoning is working.
Lead is common in the environment so it is often found in the body in low levels. Small amounts in adults are not thought to be harmful. However, even low levels of lead can be dangerous to infants and children. It can cause lead poisoning that leads to problems in mental development.
Less than 20 micrograms/dL of lead in the blood
Less than 10 micrograms/dL of lead in the blood
Note: dL = deciliter
Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
The examples above show the common measurements for results for these tests. Some laboratories use different measurements or may test different specimens.
What abnormal results mean
Adults who have been exposed to lead should have blood lead levels below 40 micrograms/dL. Treatment is recommended if:
You have symptoms of lead poisoning
Your blood lead level is greater than 60 micrograms/dL.
Blood lead level of 10 micrograms/dL or greater requires further testing and monitoring.
The source of lead must be found and removed.
A lead level greater than 45 micrograms/dL in a child's blood usually indicates the need for treatment.
Treatment may be considered with a level as low as 20 micrograms/dL.
Markowitz M. Lead poisoning. In: Kliegman RM, Stanton BF, St. Geme JW, Schor NF, Behrman RE, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, Pa.: Saunders Elsevier; 2011:chap 702.
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.