This indicator uses census data to provide information about the number of homes built before 1950 and homes built from 1950-1979. Living in an older home is one risk factor that can contribute to higher blood lead levels in children. Census data do not account for the number of older houses that have been renovated or have had lead removed; and this indicator does not consider other sources of lead in the community.

This indicator provides information on the number of children tested each year for blood lead. This information is used to direct resources for testing and management of cases with blood lead levels (BLLs) greater than 5 µg/dL and can be used to monitor trends over time. The data are used to better understand and interpret BLL surveillance, compare testing and BLLs within and across the states, and monitor progress towards eliminating BLLs greater than 5 µg/dL.

This indicator uses data collected by state and local childhood lead poisoning prevention programs. It provides information about blood lead testing and BLLs among children born in the same year, known as a birth cohort. These data can be used to identify and monitor changes in blood lead levels over time and to monitor progress toward reducing and preventing exposure to lead in children.

Data Limitations

These are some important limitations to understand about the use of blood lead testing data:

• The analysis uses the county of the child's residence at the time of the test, which may be different from the county where the child was exposed to lead.
• Counties are not homogenous with respect to the distribution of lead hazards or risk factors for lead exposure.
• Number and percent of BLLs reported through surveillance data cannot be interpreted as prevalence or incidence for the population as a whole.
• State-to-state comparisons must be made cautiously and require additional information about the states' testing practices, confirmatory testing practices, and reporting laws.

Related Indicators

Living in poverty is another risk factor that can contribute to higher blood lead levels in children. Census data about poverty can also be found in the Populations and Vulnerabilities section of the Tracking Network.

See the Biomonitoring: Population Exposures section of the Tracking Network for data on the concentration of lead in blood for the U.S. population.