What do lead testing results mean?

What is a lead blood test? | How to test for lead in children | Lead levels in children | Lead poisoning | Symptoms | Treatment | Prevention

Lead is a natural element that was previously used in all sorts of products, from gasoline and paint to cosmetics. It’s dangerous when ingested or absorbed through your skin. It accumulates in the body—stored in bones and teeth—and causes a variety of serious health problems. The most common way that people are exposed is through ingesting or breathing in particles from lead paint—often from living in or renovating homes built before 1978 (when lead paint was banned).

It’s important that all young children be tested for lead, as early lead exposure may not have any symptoms. Yet, even very small amounts can be damaging to children’s nervous system, intelligence, attention span, and academic achievement, according to the U.S. Centers for Disease Control and Prevention (CDC). Here, learn more about lead testing and how to prevent lead exposure in the first place. 

What is a lead blood test?

A lead blood test measures the amount of lead present in your body, or your blood lead level. Children are routinely tested at their 12 and 24 month well-child checkups. “Because kids under [age] 6 are more likely to put items in their mouth, they’re at the highest risk,” explains Samuel Werner, DO, a family medicine physician at Family Osteopathy in New Jersey. The timing of testing is intentional. When kids are starting to crawl or walk—and putting everything in their mouths—they can easily ingest lead particles. 

Adults may be tested if their history indicates high risk, and they have symptoms like belly pain, fatigue, or memory loss. Some high-risk categories for lead exposure include:

• Living in a house built before 1960 or a home built before 1978 with recent renovations or chipped paint
• Recent immigration to the United States
• Having parents who work in a job with regular lead exposure
• Living near a factory whose byproducts could result in lead exposure in soil

Pregnant women may be tested because high levels of lead can be passed on to the developing baby.

Lead exposure may not cause any symptoms until it reaches toxic levels and causes health problems. “Testing for lead exposure helps us identify where the exposure is coming from by checking out the home environment and taking steps to help around the home if needed,” says Tiffany Kimbrough, MD, a pediatrician at the Children’s Hospital of Richmond at VCU in Virginia. 

How to test for lead in children

Lead blood tests can be done in two ways: 

1. A finger-prick or heel-prick (capillary) test: This is the easiest and first blood lead test, done similarly to checking blood sugar levels for people with diabetes. The finger-prick or heel-prick blood sample usually has quick results. 
2. A traditional blood draw, or venous blood draw: Blood is drawn from a vein. This test is commonly done to confirm the results of a prick test if initial results show elevated blood lead levels. Lab results usually take several days to process, but are more accurate and sensitive to lower levels than a finger-poke. 

“This second test is needed because sometimes children will have lead dust present on their fingers that causes a falsely high result,” says Dr. Kimbrough, “so the venous check is more accurate.” 

There is no preparation required, such as having your child fast, before either type of test. Your child’s healthcare provider may ask for your help keeping your child calm and still, by having your child sit in your lap during the test. If the test results are negative, and your child isn’t in a high-risk environment or otherwise showing lead poisoning symptoms, further testing isn’t needed. 

Both private insurance and Medicaid typically cover the cost of lead screenings for children.

Lead levels in children

Normal lead levels should be less than 3.5 micrograms per deciliter (mcg/dL), according to the CDC. A 2007 study from Environmental Health Perspectives has shown even this low level can negatively affect children. 

“There is no true safe level of lead in growing and developing children,” says Jean Moorjani, MD, a pediatrician at Orlando Health Arnold Palmer Hospital for Children. “If your child has elevated lead levels, your doctor may recommend closer monitoring or medical treatment.” 

If your child’s lead test results are greater than 3.5 mcg/dL, your healthcare provider will provide counseling to reduce lead exposure and recommend a follow-up test after a set amount of time has passed to confirm that levels are remaining stable or decreasing.

According to the CDC

Lead poisoning

Lead poisoning occurs when lead builds up to toxic levels in the body. This can take months or years depending on the level of exposure. Lead poisoning has physical and mental health effects and can even be fatal. According to the World Health Organization (WHO), lead exposure caused 900,000 deaths worldwide in 2019. 

Some household items and environmental risk factors that contribute to lead poisoning including:

• Old paint in homes built before 1978
• Water that comes from old pipe systems
• Toys, jewelry, and candy imported from other countries 
• Some pottery and ceramics
• Living near an airport or factory where lead can enter the soil 
• Imported home remedies—for example, azarcon and greta are powders that can have a high lead content, and are used as an Hispanic traditional medicine for digestive issues

Lead may not be present in your home but it could contaminate your child’s school or child care facility.

Symptoms

The symptoms of pediatric lead poisoning might not immediately happen, says Dr. Werner, “and often the lowest levels can have subtle but long-lasting effects on behavior and development.”  Signs to watch for in your child include: 

• Headache
• Hair loss
• Vomiting
• Stomach pain
• Constipation
• Confusion
• Muscle weakness
• Seizures

Treatment

Lead poisoning is considered a public health problem. At a level above 5 mcg/dL, the state health department is notified so they can conduct a risk assessment of your home environment to identify potential sources for lead and offer case management. They can help you create a plan to reduce any further exposure. Children will have additional lead testing afterward with ongoing developmental screenings “since different neurodevelopmental effects may not be immediately obvious,” Dr. Werner adds. Treatment may include the following.

Dietary changes

Making sure your child has a proper diet can help protect against elevated lead levels. Iron and calcium bind to lead and prevent it from being absorbed. Milk, yogurt, cheese, and dark leafy vegetables are good sources of calcium. Iron-fortified cereals, seafood, and poultry are good sources of iron. Calcium may block iron from being absorbed, so it’s a good idea to eat calcium-rich foods separately from iron-rich foods. Vitamin C can boost iron storage, so you can give your child citrus fruits, cantaloupe, tomatoes, or bell peppers along with iron-rich foods. 

Early intervention

Because lead exposure can cause developmental problems or deficits at school, early intervention services are key. These programs are typically offered to children younger than 3 years of age with developmental or educational delays by your state’s department of health. They can help to decrease issues caused by lead exposure. The earlier these services are used, the more successful they are. You can find the contact information for your local health department here.

Chelation therapy

“Levels of 44 mcg/dL [or greater] would lead most healthcare providers to recommend hospitalization and chelation therapy,” explains Dr. Moorjani. However, in some circumstances, providers might choose to also treat someone with a level below that, especially if symptoms are present. 

Chelation therapy involves giving your child a medication that binds to (or chelates) lead. This medication is typically given by mouth or injected either into a muscle or a vein. Oral succimer (Chemet) is usually given for 14 days, while injectable medication such as edetate disodium calcium (EDTA) is given in two courses, with five days of medication for each course. These medications break down the lead particles in order to make them less harmful. Broken down lead leaves the body through urine.  While chelation can remove lead from the body, sometimes permanent damage has already been done to the brain and kidneys. 

Untreated lead poisoning can be life-threatening, so if you suspect your child has been exposed, don’t delay having them tested by a healthcare professional. Parents shouldn’t give home remedies to try to lower a child’s blood lead levels. “The remedies often are dangerous on their own, and don’t work,” Dr. Werner says. 

Prevention

Childhood lead poisoning prevention strategies are the best remedy for lead exposure. There are steps you can take to make your environment safer for everyone, such as:

• Conduct a lead water test. Or, consult the water safety reports from the Environmental Protection Agency’s (EPA).
• Test the paint in your home for lead. If you know you have lead-based paint, avoid sanding it so dust isn’t produced. Check for peeling paint regularly and fix lead hazards using approved methods. Use lead-safe work methods when you are repainting or renovating if you have an older home. Use the EPA’s guide on how to test for lead paint.
• Prepare nutritious meals that are high in iron and calcium.
• Remove shoes before entering your home to avoid tracking in contaminated soil.
• Dust surfaces on a regular basis.
• Wash hands frequently, and teach your children not to put their hands in their mouths.
• Use a water filter, or let the water run to flush out the pipes before using. 
• If you work in an industry that exposes you to lead, make sure you aren’t bringing lead dust into the home.

If you have any concerns when it comes to lead exposure, don’t hesitate to reach out to your healthcare provider to get a lead test. The earlier your child is tested, the sooner treatment can begin. For more information on lead and lead poisoning prevention, read the CDC’s Lead FAQs.