Testing for Blood Lead Levels

This section provides information on blood lead testing, and it answers the following questions:

What is blood lead testing?

A blood lead test is a quick and easy test. A little blood is taken from the finger (capillary or finger prick test) or arm (venous test) and checked for lead. The arm test is more accurate than the finger test because lead on the finger can contaminate the blood sample.

Where is blood lead testing available?

Testing is available in many places. Healthcare providers (doctors and health clinics) do most of the blood lead testing for young children. In most states and cities, the public health department runs a childhood lead poisoning prevention program (CLPPP). CLPPPs work to make sure all young children are tested for lead poisoning, especially those who don't have healthcare or any other way to get tested for lead. CLPPPs also talk to healthcare providers to make sure they are:

  • teaching families about lead poisoning,
  • finding out if children are at high risk for exposure to lead,
  • testing blood for lead.

A list of clinics can be found online at the Chicago Department of Public Health (CDPH) website. Some of the clinics offer free blood lead testing in Chicago.

Who should be tested for lead exposure?

Like most states and cities, Illinois and Chicago require some or all children to be tested for lead at certain ages. This is called the blood lead screening schedule. Children can be tested at other times also.

Healthcare providers can find out if a child is at high risk for lead poisoning by asking parents or guardians certain questions during regular visits. If parents or guardians answer "yes" or "don't know" to any of the following questions, the child may be at high risk for lead poisoning, and may need to be tested for lead more often.

  • they live in a high-risk community or zip code;
  • they receive Medicaid or help from the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC);
  • they live in an older home;
  • they live in a home that has chipping or peeling paint;
  • they live with people who may be exposed to lead at work or from a hobby;
  • their regularly visit an older home or building;
  • they live or have lived near an active lead smelter, a battery recycling plant, or another industry likely to release lead into the air;
  • their home has been renovated recently or is being renovated; or
  • other children in the family or neighborhood have tested high for lead.

At what age should children first be tested for lead?

The Centers for Disease Control recommends that children at high risk for lead poisoning should have their first blood lead test when they are 12 months old.

In Illinois, children who live in a high-risk area (or zip code) of Illinois or who take part in a public assistance program like Medicaid or Kidcare are at high risk for lead poisoning and should have their first blood lead test when they are 12 months old.

Children who live in a low-risk area (or zip code) need a blood lead test when they are 12 months old only if their healthcare provider thinks they are at high risk for lead poisoning for other reasons.

In Chicago, all children should be first tested at six or nine months of age.

How often should children be tested for lead if they do not have an elevated blood lead level (EBLL)?

The Centers for Disease Control recommends that children at high risk for lead poisoning should be tested again at 24 months if their blood lead test at 12 months was normal. Three to six year olds at high risk for lead poisoning should also be tested for lead if they have never been tested for lead before.

In Illinois, children who live in a high-risk area, or who take part in a public assistance programs are at high risk for lead poisoning and should be tested again at 24 months of age.

Children who live in a low-risk area (or zip code) should be tested again at 24 months old only if their healthcare provider thinks they are at high risk for lead poisoning for other reasons.

In Chicago, all children should first be tested for lead at 6 or 9 months. If their blood lead levels (BLLs) are normal, they should be tested again every six months until 24 months, and then once a year until they're six years old.

What do blood lead test results mean?

The result of a blood lead test is a number, which tells you how much lead is in the blood. It is called a blood lead level (BLL). To understand the meaning of a BLL, it is important to know how the sample was taken. Results from finger tests (capillary or finger prick tests) are sometimes higher than the real blood level because of lead on the child's fingertip. Children with a finger test result of 10 ug/dl (micrograms per decileter) or greater will need to get an arm test.

A child with a BLL from 10 to 19 ug/dl is at the "level of concern." This means the child's BLL should be watched. It is important to identify sources of lead exposure and possibly control them. Healthcare providers should teach parents or guardians about possible sources of lead hazards and give them information on how to prevent lead poisoning. Parents or guardians may also receive information about social services for the affected child.

In Illinois, children with a blood lead test result of 15 ug/dl or greater who get a second blood lead test result at least 5 ug/dl greater than the first one, need to have their home inspected for lead. If lead hazards are found, they will have to be controlled.

A child with a BLL from 20 to 44 ug/dl needs a full medical evaluation. The child should get a medical evaluation within 10 days of getting the blood lead test result. A nurse from the local public health department will visit the child's home to help parents learn ways to reduce the child's exposure to lead. Children with BLLs from 20 to 44 ug/dl should get monthly blood lead tests until lead exposure is reduced and their BLLs go down.

In Illinois, children with a BLL of 25 ug/dl or greater will get their home inspected by a licensed risk assessor. And in Chicago, children with a BLL as low as 15 ug/dl will get their home inspected. If lead hazards are found, they will have to be controlled.

A child with a BLL from 45 to 69 ug/dl needs a full medical evaluation and medical treatment within 48 hours. Healthcare providers with little experience treating lead poisoned children should consider sending the child to an expert or a lead poisoning clinic. The child may have seizures, vomit, have stomach cramps, constipation, or be very tired. A nurse from the local public health department will visit the child's home within 5 working days to help parents or guardians learn ways to reduce the child's exposure to lead. A certified risk assessor will also inspect the child's home within 5 working days. If lead hazards are found, they will have to be controlled.

A child with a BLL of 70 ug/dl or greater is a medical emergency. The child will need to stay in a hospital and receive immediate medical treatment. A nurse from the local public health department will visit the child's home within 24 to 48 hours to help parents or guardians learn ways to reduce the child's exposure to lead. Parents or guardians will also receive information about social services for the affected child. The home will be inspected for lead within 24 to 48 hours, and any lead hazards found have to be controlled immediately.

Visit the Chicago Department of Public Health website for the Chicago blood lead testing guidelines.

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