Lead Poisoning Data and Data Analysis

The 2014 Report on Childhood Lead Poisoning in Wisconsin (P-01202, PDF, 1.4 MB) is now available.

The Wisconsin Environmental Public Health Tracking Program webpage is a resource that allows you to query data on childhood lead poisoning in Wisconsin and other environmental and health topics.

Information on this page has been organized into three categories.  Please choose one of the following tabs.

Annual Numbers

The annual blood lead testing reports on childhood lead poisoning in Wisconsin include the number of children tested and poisoned and the number of cases (level of lead in blood that requires intervention) at age one, age two, ages zero to five, and ages three to five not previously tested for each local health department jurisdiction. For 2003 to 2010, the reports also include prevalence rates and rates for children enrolled in Medicaid and WIC programs.

These annual reports for Wisconsin comprise local health department jurisdiction and statewide totals and rates of the number of children tested for lead and found to be lead poisoned. From 1991 - 2011, the Centers for Disease Control and Prevention (CDC) defined lead poisoning as a blood lead level (BLL) of 10 micrograms per deciliter (mcg/dL) or greater and recommended public health intervention for those children. According to Wisconsin Statute, a child with a BLL of 20 mcg/dL or greater represents a "case" and requires public health intervention. Thus, the reports also include the number of cases of children with extremely high levels of lead by health department jurisdiction.

In 2012, CDC lowered the reference level for intervention from 10 mcg/dL to 5 mcg/dL, increasing the number of Wisconsin children under age 6 found to be lead exposed by a factor of five. The data report for 2011 - 2013 is in a different format from previous years. In addition to the number of children at 10 mcg/dL or greater, it includes the number and rate (percent) of children with BLLs between 5 and 9 mcg/dL. Also included is a time trend of the number of Wisconsin children tested for lead from 2001 - 2013 and a time trend for those found to be lead poisoned in that same time frame. In 2014, the report only reports BLLs of 5 mcg/dL or more.

Reports are available as PDF files for the following years:

2003 P-00817-2003 (PDF, 43 KB)

2006 P-00817-2006 (PDF, 43 KB)

2009 P-00817-2009 (PDF, 55 KB)

2014 P-00817-2014 (PDF, 178 KB)

2004 P-00817-2004 (PDF, 44 KB)

2007 P-00817-2007 (PDF, 209 KB)

2010 P-00817-2010 (PDF, 78 KB)

2015 P-00817-2015 (PDF, 190 KB)

2005 P-00817-2005 (PDF, 50 KB)

2008 P-00817-2008 (PDF, 211 KB)

2011-2013 P-00665 (PDF, 4.0 MB)

 

Time Trends

This tab contains graphs showing the trends of testing for lead poisoning and identifying childhood lead poisoning in Wisconsin from 2001 to 2013.

Statewide surveillance of childhood lead poisoning in Wisconsin has been conducted since 1991. Lead poisoning in children is defined in Wisconsin Statute Chapter 254.11 (9) as a level of lead in the blood of 10 or more micrograms per 100 milliliters of blood. Due to the wealth of research showing significant learning, behavioral and lifelong health effects of lead on children at levels below 10 mcg/dL, in May 2012, CDC lowered the level of concern to the reference value of 5 mcg/dL for precautionary action. This increases the number of Wisconsin children found to be lead exposed by a factor of 5.

Tested for Lead

During the years 2001 to 2013, the number of children tested for lead poisoning remained static from 2004 to 2006 at about 80,000 children per year and then increased in 2007 through 2011 to more than 100,000 children annually. Since then the number of children under age 6 tested for lead started to decline again.

Graph showing number of children tested for lead in Wisconsin

Poisoned by Lead

The time trend for the number of children found to be lead poisoned (10 mcg/dL) was on the decline from 2000 to 2013; however, looking at the number of children at the lower reference value of 5 mcg/dL, the increase in the number of children is sizeable.

Instances of lead poisoning in children in Wisconsin

Risk Factors

Age of Child

Research indicates that a child’s BLL tends to be highest between 18 and 36 months of age. This is attributed to frequent hand-to-mouth behavior and the increase in mobility during the second and third years which makes lead containing dust more accessible to the child.

Current screening policy in Wisconsin includes a recommendation to test children who are at risk for lead poisoning at one year of age so that, if lead exposure has occurred, it can be identified early and interventions can take place to reduce the BLL. However, it is also very important that children be tested again at two years of age or later when they become more mobile and their risk of exposure to lead is greater. Therefore, a normal blood lead test at one year of age does not mean the child is not at risk for lead poisoning later on.

The figure below shows that most Wisconsin children are tested only when they are 12 months of age. However the incidence of lead poisoning (that is, the first identification of lead poisoning) is highest around two years of age. In other words, while half as many children were tested at age two, more than twice as many were first found to be lead poisoned at age two.

Lead Incidence graph

Age of Housing

National data have shown that children who live in old housing, where LBP is more prevalent, are at greater risk for lead poisoning than children who live in newer housing.  This same relationship is evident in Wisconsin, where a previous analysis found that 90% of children first identified with lead poisoning from 1996–2006 lived in homes that were built before 1950. That analysis matched addresses in tax assessor files from 16 Wisconsin cities with addresses of children who had received blood lead tests, and found that the risk of a child becoming lead poisoned was 6.4 times greater for tested children living in dwellings built before 1950 compared to children living in post-1950 dwellings.

Age of Housing

Family Income

Children from low income families in Wisconsin are at greater risk for lead poisoning, largely because they have limited options for selecting housing. A family with a child who receives either Medicaid health care benefits or vouchers from the Supplemental Food Program for Women, Infants and Children (WIC) is considered low income. 

The Wisconsin Medicaid Program collaborates with the WCLPPP in linking program data to determine blood lead testing and lead poisoning among Medicaid-enrolled children. This data linkage has demonstrated that, despite the federal testing policy, many Wisconsin children enrolled in Medicaid are not tested at the appropriate ages. In 2014, only 62% of one-year olds, 48% of two-year olds, and 16% of three- through five-year olds who were not previously tested were tested. Only 42% of Medicaid-enrolled children received the appropriate testing at both one and two years of age. See the table below.

Age Total Eligible Test in Year Percent Tested in Year
1 Year 35,944 22,261 61.93%
2 Years 34,420 16,629 48.31%
3-5 Years, not previously tested 19,581 3,116 15.91%

The data linkage also shows that Medicaid-enrolled children in Wisconsin are at three times greater risk of lead poisoning than non-Medicaid enrolled children. In 2014, 88% of the children found to be lead poisoned were enrolled in Medicaid. If all children on Medicaid had been appropriately tested during 2014, it is likely that a number of additional children would have been identified as lead poisoned and could have received the interventions they needed. This has led to increased efforts within Wisconsin to assure compliance with the 1992 federal requirement that Medicaid-enrolled children receive blood lead tests at ages 12 months and 24 months, and through age five years if not previously tested.

WIC projects in Wisconsin are strong partners in assuring that children who are at risk for lead poisoning receive the blood lead testing they need. In 2014, 52.1% of Medicaid-enrolled children under five years of age who received a blood lead test, were tested by a WIC provider, rather than their primary health care provider.  While blood lead testing is not a requirement for WIC participation, many WIC projects have voluntarily established successful testing programs and act as a safety net, testing children who might otherwise be missed.

Race/Ethnicity

Wisconsin children of all races and ethnicities have been identified with lead poisoning. However, minority populations share a greater burden of the lead poisoning problem. The figures and table below indicates the percent of children tested by racial and ethnic group, as well as the percent identified with lead poisoning. While White children comprised the largest proportion of children tested (44.2%) as well as the largest proportion of children aged less than six years in Wisconsin, this is not true when looking at the distribution of race/ethnicity among children identified with lead poisoning. Rather, lead poisoning rates are highest among Black children, followed by Hispanic and Asian children. While Black children are only one quarter of the children tested, they represent nearly half of the children found to be lead poisoned in Wisconsin.

Lead testing chart by ethnicity

Race/Ethnicity Total Tested Total with BLL of ≥ 5 µg/dL BLL ≥ 5 µg/dL as % of Children Tested Percent of All Children under Age 6
White


27,984

803  2.9%  72.0%
Black 16,221 1,616 10.0% 10.61%
Hispanic 15,096 753

5.0%

12.18%
Asian 2,942 157 5.3% 3.92%
American Indian/ Alaskan Native 1,030 23 2.2% 1.33%

 

 

 

 

 

 

 

 

 

Pockets of Risk

While lead poisoning is a risk statewide, significantly higher rates are seen in certain communities or parts of communities with higher prevalence of older housing and other risk factors for lead poisoning. The local health department (LHD) jurisdictions with the top ten highest rates are the four cities of Menasha, Milwaukee, Racine and Watertown and six counties of Buffalo, Green Lake, Pepin, Richland, Rock and Sheboygan (see the table below). The prevalence rates of lead poisoning in these jurisdictions range from 5.1% to 8.6% and are considerably higher than the 2014 statewide rate of 4.5% (see Annual Report 2014 for a full listing of prevalence rates for all LHDs). These prevalence rates are for the entire LHD jurisdiction; smaller geographical areas such as individual neighborhoods and census tracts may have much higher rates of poisoning.

Local Health Department Total Tested Total with BLL of 5 µg/dL of more BLL ≥ 5 µg/dL as Percent of Children Tested
City of Milwaukee 26,097 2,244 8.6%
City of Watertown 535 45 8.4%
Buffalo County 178 13 7.3%
Sheboygan County 1,215 76 6.3%
City of Racine 2,467 153 6.2%
Rock County 2,354 142 6.0%
Green Lake County 250 14 5.6%
Pepin County 90 5 5.6%
City of Menasha 254 14 5.5%
Richland County 175 9 5.1%
Statewide 87,987 3,922 4.5

Tested 5 mcg/dL or above: Number of unduplicated children who had a capillary or venous blood lead level of 5 micrograms per deciliter (mcg/dL) or above. If the test was a capillary sample followed within 3 months by a venous test, the date, place and result of the venous test result was used.

Home Page - Lead-Safe Wisconsin

Last Revised: September 14, 2016