Test Overview
This test measures the amount of lead in a person's blood. Lead is a
poisonous (toxic) metal that can damage the brain and other parts of the body.
A lead test may be done on blood drawn from the vein, a finger (finger
stick), or the heel (heel stick).
A person can be exposed to
lead:
- By eating or drinking lead-contaminated foods,
water, or other material (such as paint chips).
- By breathing dust
or smoke containing lead.
- Through skin contact with lead.
There is no safe age to be exposed to lead. Adults can have
problems from
lead poisoning, but it is most harmful to children
younger than age 6 (especially those younger than age 3) because it can
permanently affect their growth and development. A pregnant woman who is
exposed to lead can pass it to her baby
(fetus). Lead can also be passed to a baby through the
mother's breast milk.
Why It Is Done
A lead blood test is done to:
- Diagnose lead poisoning.
- See how
well treatment for lead poisoning is working.
- Look for lead
poisoning in people who work with lead or lead products or live in places where
the chance of poisoning is high, such as in a large city.
- Check the amount of lead in people who live with or play with children who have lead poisoning.
How To Prepare
No special preparation is required
before having this test.
Be sure to tell your doctor if you are
using any herbal medicines.
How It Is Done
Blood tests for lead should be done by a
lab experienced in
proper technique.
Blood sample from a heel stick
For a heel stick
blood sample, several drops of blood are collected from the heel of your baby.
The skin of the heel is first cleaned with alcohol and then punctured with a
small sterile lancet. Several drops of blood are collected in a small tube.
When enough blood has been collected, a gauze pad or cotton ball is placed over
the puncture site. Pressure is maintained on the puncture site briefly, and
then a small bandage is usually applied.
A heel stick must be done
carefully to prevent contamination of the sample from lead on the skin. If a
heel stick blood sample comes back positive for lead, a sample of blood from
your baby's vein will be tested to confirm the results.
Blood sample from a vein
The health professional
taking a sample of your blood will:
- Wrap an elastic band around your upper arm to
stop the flow of blood. This makes the veins below the band larger so it is
easier to put a needle into the vein.
- Clean the needle site with
alcohol.
- Put the needle into the vein. More than one needle stick
may be needed.
- Attach a tube to the needle to fill it with
blood.
- Remove the band from your arm when enough blood is
collected.
- Put a gauze pad or cotton ball over the needle site as
the needle is removed.
- Put pressure on the site and then put on a
bandage.
How It Feels
Blood sample from a heel stick
A brief pain, like
a sting or a pinch, is usually felt when the lancet punctures the skin. Your
baby may feel a little discomfort with the skin puncture.
Blood sample from a vein
The blood sample is taken
from a vein in your arm. An elastic band is wrapped around your upper arm. It
may feel tight. You may feel nothing at all from the needle, or you may feel a
quick sting or pinch.
Risks
Heel stick
There is very little chance of a
problem from a heel stick. A small bruise may develop at the site.
Blood test
There is very little chance of a
problem from having a blood sample taken from a vein.
- You may get a small bruise at the site. You
can lower the chance of bruising by keeping pressure on the site for several
minutes.
- In rare cases, the vein may become swollen after the blood
sample is taken. This problem is called phlebitis. A warm compress can be used
several times a day to treat this.
- Ongoing bleeding can be a
problem for people with bleeding disorders. Aspirin, warfarin (Coumadin), and
other blood-thinning medicines can make bleeding more likely. If you have
bleeding or clotting problems, or if you take blood-thinning medicine, tell
your doctor before your blood sample is taken.
Results
This test measures the amount of lead in
the blood. Lead is a poisonous (toxic) metal that can damage the brain and
other parts of the body. A small amount is present in most people.
The reference values listed here are just a guide. These ranges vary from lab to lab. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other things. This means that a value that falls outside the reference values listed here may still be okay for you.
Results are usually available within 1 week.
Your doctor will likely want to do more evaluation and another blood lead level test if:1, 2
What Affects the Test
You may not be able to
have the test or the results may not be helpful if your skin is contaminated with lead. Low levels of lead
can be found almost anywhere, including on the skin.
What To Think About
- Timed urine tests may be done to check the amount of lead in urine and/or to keep track of the amount of lead being removed from your body during chelation therapy.
- The U.S. Occupational Safety and Health Administration (OSHA)
requires companies to test the blood of employees who work with lead. Results
need to be reported to the local health department if 2 or more blood lead
levels are above 10 mcg/dL. For more information, see OSHA's website at www.osha.gov.
References
Citations
- Fischbach FT, Dunning MB III, eds. (2009).
Manual of Laboratory and Diagnostic Tests, 8th ed.
Philadelphia: Lippincott Williams and Wilkins.
- Centers for Disease Control and Prevention (2012). Announcement: Response to the Advisory Committee on Childhood Lead Poisoning Prevention report, low level lead exposure harms children: A renewed call for primary prevention. MMWR, 61(20): 383. Also available online: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6120a6.htm?s_cid=mm6120a6_w.
Other Works Consulted
- Committee on Environmental Health, American Academy of
Pediatrics (2005, reaffirmed 2009). Lead exposure in children: Prevention, detection, and
management. Pediatrics, 116: 1036–1046. Also available
online: http://www.pediatrics.org/cgi/content/full/116/4/1036.
Credits
| By | Healthwise Staff |
|---|
| Primary Medical Reviewer | John Pope, MD - Pediatrics |
|---|
| Specialist Medical Reviewer | R. Steven Tharratt, MD, MPVM, FACP, FCCP - Pulmonology, Critical Care Medicine, Medical Toxicology |
|---|
| Last Revised | July 26, 2012 |
|---|
Fischbach FT, Dunning MB III, eds. (2009).
Manual of Laboratory and Diagnostic Tests, 8th ed.
Philadelphia: Lippincott Williams and Wilkins.
Centers for Disease Control and Prevention (2012). Announcement: Response to the Advisory Committee on Childhood Lead Poisoning Prevention report, low level lead exposure harms children: A renewed call for primary prevention. MMWR, 61(20): 383. Also available online: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6120a6.htm?s_cid=mm6120a6_w.