Blood Lead Reference Value

  • CDC now uses a blood lead reference value of 5 micrograms per deciliter (µg/dL) to identify children with blood lead levels that are higher than most children, that is, children in the highest 2.5% of blood lead levels.
  • The blood lead reference value is based on the 97.5th percentile of the National Health and Nutrition Examination Survey (NHANES) blood lead distribution in children ages 1-5 years. The current reference value is based on NHANES data from 2007-2008 and 2009-2010.
  • CDC will assess the NHANES data every 4 years using the two most recent survey cycles of available data to determine if the blood lead reference value should be updated.
  • Until 2012, children were identified as having a blood lead “level of concern” if the test result was 10 or more micrograms per deciliter (µg/dL) of lead in blood. CDC is no longer using the term “level of concern” and is instead using the reference value to identify children who have been exposed to lead and require follow-up case management.
  • CDC provides recommendations for follow-up and case management of children based on confirmed blood lead levels.

Additional Resources