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Heavy Metal Index

Blood Lead Reference Value (3.5 µg/dL)

Source

Summary The CDC Blood Lead Reference Value (BLRV) of 3.5 µg/dL is the screening threshold used to identify US children with elevated blood lead concentrations relative to most US children.

Page snapshot
Cited by7 pages
Metals measured1
Evidence tierA
Year2021

Summary

The CDC Blood Lead Reference Value (BLRV) of 3.5 µg/dL is the screening threshold used to identify US children with elevated blood lead concentrations relative to most US children. The BLRV is set at the 97.5th percentile of blood lead values in US children ages 1 to 5 years from NHANES 2015-2016 and 2017-2018 cycles, meaning children at or above the BLRV represent the top 2.5 percent of measured blood lead. The value is not a health-based threshold (lead has no demonstrated safe blood level for children); it is a population-percentile-based screening tool for public health intervention. The BLRV is the input to FDA’s Closer to Zero Interim Reference Level for dietary lead, derived through dietary-to-blood-lead conversion factors with a 10x safety factor.

Key numbers

ParameterValue
Current BLRV3.5 µg/dL
Statistical basis97.5th percentile of blood lead in US children ages 1-5
Source surveyNHANES 2015-2016 and 2017-2018 cycles
Population represented at-or-above BLRVTop 2.5 percent of measured US child blood lead
Year of update from prior 5 µg/dL value2021

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Update history

The five most recent substantive edits to this page, classified major (evidence or structure moved), correction (a published value or statement was wrong and has been fixed), or minor (narrative rewritten without changing the underlying evidence). Each description is derived from what the edit did to this page; the linked commit is the authoritative record, routine regeneration passes are excluded, and the full version history lives in git. When DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.

CommitDateChangeDescription
a8052bb2026-08-09major4 sections added; narrative text revised