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Lead-Safe Wisconsin: Childhood Lead Poisoning Data and Data Analysis

The Wisconsin Childhood Lead Poisoning Prevention Program collects data to help lead-poisoned children. Program staff analyze the data to identify at-risk communities and other trends.

Use this page to learn about Wisconsin's childhood lead poisoning and testing rates. You can also find links to data publications and resources. Email the Wisconsin Childhood Lead Poisoning Prevention Program at DHSLeadPoisoningPrevention@dhs.wisconsin.gov with questions about this content.

Childhood Lead Poisoning Data Explorer Map

The interactive Childhood Lead Poisoning Data Explorer Map shows census tract level childhood lead poisoning data for Wisconsin children under age 6. The application also contains interactive maps of environmental and social characteristics that may be associated with an increased risk of lead exposure and lower blood lead testing rates among children.

View the Childhood Lead Poisoning Data Explorer Map

Wisconsin Childhood Lead Poisoning Data Explorer Map

Using maps to display lead poisoning data helps us:

  • Identify where the risk of lead exposure is greater.
  • Target efforts to control lead hazards before they poison children.
  • Target blood lead testing where children are at higher risk for poisoning.
  • Connect children with lead poisoning to recommended services.
  • Monitor progress toward eliminating childhood lead poisoning.
  • Identify and monitor trends in sources of lead exposure for children.
  • Develop and evaluate lead poisoning interventions and programs.

Learn about the data displayed in the application

The Childhood Lead Poisoning Data Explorer contains the following data at the census tract level:

Percent of children poisoned

Percent of children under age 6 years old poisoned with blood lead levels of ≥5 micrograms per deciliter (µg/dL). Note: The CDC (Centers for Disease Control and Prevention) now uses a reference value of ≥3.5 µg/dL; however, no safe blood lead level in children has been identified.

The percent of children poisoned is calculated as the number of children poisoned divided by the number of children tested. This measure is the most accurate one to use for comparisons between geographic areas of the state.

Number of children poisoned

Number of children under age 6 years old poisoned with blood lead levels of ≥5 micrograms per deciliter (µg/dL). Note: The CDC now uses a reference value of ≥3.5 µg/dL; however, no safe blood lead level in children has been identified.

The number of children poisoned is a count value. Some areas of the state will have higher numbers of poisonings simply because there are more people living there.

Number of children tested

Number of children under 6 years old tested for lead poisoning. Children who received multiple tests are only counted once per year. The census tract refers to the child’s home address, not the place where the child was tested.

Age of housing pre-1950

Percentage of housing built prior to 1950. Prior to 1950, it was common for lead-based paint to be used inside and outside homes. Communities with a high proportion of their housing stock built before 1950 are at greater risk of higher blood lead levels in children. However, this census data does not account for the number of older houses that have been renovated or have had lead removed.

Age of housing pre-1980

Percentage of housing built prior to 1980. Prior to 1978, it was common for lead-based paint to be used on a home’s exterior. Communities with a high proportion of their housing stock built before 1978 are at greater risk of higher blood lead levels in children. However, this census data does not account for the number of older houses that have been renovated or have had lead removed.

Housing insecurity

Percent of households that spend more than 30% of income on housing costs, such as rent. Often these families have fewer affordable housing options and are limited to low quality and unsafe housing that is cheaper to buy or rent.

Renter households

Percent of households occupied by renters. Families who rent will often have decreased agency and power to make repairs to their home, like safely fixing chipping or peeling lead-based paint, which can increase a child’s risk of being exposed to lead.

Childhood poverty represents the percent of children under 5 years old living in poverty in the previous 12 months.

Often families living in poverty have fewer affordable and safe housing options. In addition, children in poverty may have limited access to healthcare and nutritional resources, which can worsen the effects of lead exposure.

Uninsured population represents the percent of population under 6 years old without health insurance.

A high percent of uninsured children is an indicator that children may be at risk for lead exposure and have limited access to healthcare and other social and economic supports, which may result in delayed diagnosis and treatment of lead poisoning.

Time trends

The Wisconsin Environmental Public Health Tracking Program lets you search for state and local data on childhood lead poisoning—as well as for data on other environmental public health topics. Read answers to FAQs (frequently asked questions) about the tracking program.

Join the environmental health listserv

Below you can find graphs showing the trends of the number of children tested for lead poisoning and the number of children found to be lead poisoned in Wisconsin.

Lead testing

The number of children under 6 tested for lead poisoning peaked from 2009-2011 with over 100,000 children tested per year. From 2012-2015, the number of children tested declined and then remained relatively stable at around 88,000 until 2019.

In 2020, the number of Wisconsin children tested for lead dropped significantly, and testing rates remain low:

  • In 2020, only about 65,000 children received a blood lead test (23% fewer than in 2019).
  • In 2021, only about 66,000 children received a blood lead test.
  • In 2022, only about 69,000 children received a blood lead test.
  • In 2023, only about 75,000 children received a blood lead test (12% fewer than in 2019).
Number of Wisconsin Children Tested for Lead, 2003-2023

Lead poisoning

While no safe blood lead level in children has been identified, the CDC uses a blood lead reference value to identify children with higher levels of lead in their blood compared to other children. From 2012-2021, the CDC blood lead reference value was 5 µg/dL. In late 2021, the CDC lowered their blood lead reference value to 3.5 µg/dL to better identify children with higher levels of lead in their blood compared to most children. Lead poisoning is currently defined in Wis. Stat. § 254.11(9) as a blood lead level of 5 µg/dL or more.

Over time, the percentage of tested children who have a blood lead level greater than or equal to 5 µg/dL has declined: In 2012, 6.2% of children who were tested for lead had a blood lead level greater than or equal to 5 µg/dL, compared to 3.2% in 2023. However, CDC’s updated blood lead reference value of 3.5 µg/dL will double the number of children who will be considered lead poisoned: In 2023, 6.3% of children who were tested for lead had a blood lead level greater than or equal to 3.5 µg/dL.

Percentage of Wisconsin children under age 6 with a blood lead level above CDC reference value between 2010 and 2023

Annual numbers

Lead poisoning data are reported for Wisconsin residents under age 6. While no safe blood lead level in children has been identified, the CDC uses a blood lead reference value to identify children with higher levels of lead in their blood compared to other children. This value has changed over time.

The reports below reference the blood lead level that reflected the CDC’s guidance at the time:

Glossary

 
Last revised March 14, 2024