At a glance
CDC’s Childhood Blood Lead Surveillance (CBLS) System at the national level integrates information collected by state and local health departments. State and local childhood lead poisoning prevention programs which are supported by CDC-funded cooperative agreements are required to provide childhood blood lead surveillance data to CDC. Other state and local childhood lead poisoning prevention programs may provide data on a voluntary basis.
Overview
CDC applies nationally consistent standard definitions and classifications for blood lead surveillance data from all states and local jurisdictions with public health surveillance authority. In addition, CDC applies rigorous error-checking and validation algorithms to the submitted data. This ensures only one test per individual per year is counted. Therefore, the information available from CDC may not match data reports from the individual states. States may use different case definitions for clinical and environmental management.
About 3 million blood lead test results are received by CDC each year. These reports are processed and validated. Any submission errors are reconciled with the state before being analyzed and grouped into a reportable surveillance format.
The National Surveillance Data table in the spreadsheet shows state-level blood lead test data.
Data are summarized by state, year, and blood lead level (BLL). This table represents data reported by states to the national surveillance system from 2017–2021. The data represents only a subset of state-specific data and is not a population-based estimate. Therefore, we are not able to compare states or generate national prevalence estimates.
Childhood blood lead surveillance data from before 2017 are available in the CDC Archive.
CDC lowered the blood lead reference value.
CDC recommends children with a blood lead level at or above the blood lead reference value be prioritized for medical and public health actions.
Limitations
The childhood blood lead surveillance data on CDC's website are not a population-based estimate. NHANES is the best available source for nationally-representative, population-based prevalence estimates of higher blood lead levels in U.S. children.
The blood lead surveillance data are not representative of the United States or even of an entire state or county. Not all children are at risk for lead exposure and, therefore, not all children need to receive a blood lead test. CDC recommends that states develop statewide blood lead screening plans based on local data and conditions.
Blood lead testing is initiated by healthcare providers. It is difficult to know why or how healthcare providers decide to test children for lead. Programs are designed to focus resources on areas and populations at highest risk. They also work diligently to understand the completeness and representativeness of their state or local jurisdiction-based blood lead surveillance data.
Nonetheless, these data are collected for the purposes of program management. Therefore, data cannot be accurately compared between states or between counties within a state. Percentages of children with higher blood lead levels can be affected by:
- Population size (denominator data)
- Number of children tested (within a geographical unit)
- Type of children tested (low vs. high risk)
- Testing recommendations (targeted or universal)