Lead-Safe Wisconsin: What is Lead Poisoning?
What is Lead?
Lead is a naturally occurring element found in small amounts in the earth’s crust. It was mined in Wisconsin and added as a stabilizing agent to products like:
- Gasoline
- Paint
- Plastics
- Varnish
What is lead poisoning?
In 1978, lead was banned from being added to paint and varnish for residential use because researchers found it can be toxic to humans and animals. It can damage the brain and other systems, leading to:
- Developmental delays.
- Learning disabilities.
- Reduced IQ and attention span.
- A range of other health and behavioral effects.
Lead is still present in paint and varnish in homes and child care centers built before 1978. Lead can hurt anyone, but kids under age six are most vulnerable. The damage from lead poisoning can last a lifetime. Learn more about how lead affects the mind and body by expanding the sections below.
Lead poisoning in children can result in delays in growth, behavior, and learning. Every child exposed to lead should be screened for harmful neurocognitive effects. Screening can help determine which interventions may be necessary.
Studies have found lead poisoning can cause:
Lead poisoning in children can cause academic and behavioral problems. These children can exhibit impulsivity, aggression, and short attention span.
Studies have found lead poisoning can cause academic setbacks, including:
- Lower math and reading test scores.
- Lower reading readiness.
- Lower end-of-year test scores.
- A decreased chance of being placed in an advanced or intellectually gifted program and an increased chance of having a learning disability.
- A nearly tripled risk of school suspension in the fourth grade when exposed to lead before age 3.
- Lower state test scores in the fourth grade when exposed to lead before age 6.
- Lower proficiency in math, science, and reading in third, fifth, and eighth grades.
- Lower test scores in eighth grade.
Other studies have found it can cause behavioral issues, such as an increased risk of:
- Anxiety, depression, and aggression.
- Being arrested for a violent crime.
- Cognitive problems, and disorders such as hyperactivity and impulsivity.
- Developing ADHD (attention-deficit/hyperactivity disorder), experiencing teen pregnancy, and engaging in criminal behavior.
- Developing depression and panic attacks.
- Displaying violent behavior.
- Engaging in criminal behavior later in life.
- Showing aggressive behavior in the classroom.
Lead poisoning can harm these bodily systems:
- Cardiovascular
- Cognitive
- Endocrine
- Immune
- Musculoskeletal
- Reproductive
Studies have found it can cause:
- Increased risk of early death from heart attack and stroke.
- Increased risk of cognitive deficits, such as memory loss.
- Increased risk of hypertension.
- Increased risk of kidney disease.
- Poor upright balance, coordination, and motor skills, increasing long-term injury risk.
- Delayed puberty onset in girls ages 8 to 18.
- Increased risk of spontaneous abortion, preterm birth, and low birth weight.
- Reproductive disorders, including hypertension during pregnancy and testicular dysfunction.
How does lead poison?
Lead poisoning occurs in a few common ways:
- Lead-tainted dust can get on children’s hands and into their mouths. This can happen because chipping and peeling lead-based paint in older homes is ground to a very fine dust and largely invisible. It can gather in windows, on floors, porches, and in the soil.
- Lead-based paint can be disturbed during renovations or remodeling. If the work is not conducted safely, the lead fumes and dust in the air can be inhaled or ingested by people in the area.
- Lead can also be found in:
- Drinking water service lines and fixtures.
- Soil from leaded gasoline.
- Paint and industrial emissions.
- Products such as toys, children’s jewelry, candies, and traditional remedies, like powders for arthritis.
How do we define lead poisoning?
In 2021, the CDC (Centers for Disease Control and Prevention) updated the blood lead reference value to 3.5 micrograms per deciliter (µg/dL). This level helps public health authorities identify children with higher levels of lead in their blood compared to most children. The value was previously 5 micrograms per deciliter.
Find data on childhood lead poisoning in Wisconsin based on the blood lead reference value.
Find health care guidance for lead-poisoned children.
When should children get tested for lead poisoning?
All children should get at least two lead tests by age 2. Children age 3 to 5 should get tested if they have no record of a previous test. Starting January 2024, Wisconsin recommends* testing:
- All children at age 1.
- All children again at age 2.
- Any children between ages 3 to 5 without a previous test.
*These recommendations match the federal Medicaid requirement. Additional testing may be recommended in the city of Milwaukee.
Additionally, all children under 17 years of age can be tested if:
- Their parent or guardian expresses concern about lead exposure or asks for their child to be tested for lead poisoning.
- Their health care provider becomes aware of possible lead exposure or lead poisoning risk factors.
- They are a newly arrived refugee. CDC (Centers for Disease Control and Prevention) recommends testing at arrival and again three to six months after the initial test.
To learn more about blood lead testing, visit the Lead-Safe Wisconsin: Universal Testing page and Lead-Safe Wisconsin: Pediatric Lead Testing and Reporting page.
How can we prevent lead poisoning?
We can prevent lead poisoning by getting rid of the danger before it harms children or others. Wisconsin’s goal is to eliminate the disease by making houses lead-safe, and by getting involved early to stop lead exposure.
Learn about prevention and intervention for childhood lead exposure.
Learn about lead-safe renovation in Wisconsin.
More resources
Families and health professionals can find fact sheets and other educational resources on our Lead-Safe Wisconsin: Tools for Outreach page. Visit our Lead-Safe Wisconsin: Forms and Publications page for additional lead-related publications.
Reliable sources for more information
- CDC (Centers for Disease Control and Prevention (CDC Spanish version)
- Local public health departments
- Local WIC (the Special Supplemental Nutrition Program for Women, Infants, and Children) clinics
- U.S. Department of Housing and Urban Development (HUD) (HUD Spanish version)
- U.S. Environmental Protection Agency (EPA) (EPA Spanish version)