Hidden Lead
homeprojectshidden lead
Hidden Lead Overview

Despite increased attention on childhood lead poisoning since the water crisis in Flint, Michigan, most efforts to describe the scope of the problem only focus on the children who have been tested for lead. However, no one has described how many children are not even being tested. Results of new research from the California Environmental Health Tracking Program show that many children may be falling through the cracks. Learn more below and in About the Methods.

Related documents


Infographics ( long PDF | one-page PDF )

State Level Maps ( Case Ascertainment | Percent Above 2.5 ug/dL | Percent Above 5.0 ug/dL | Percent Above 10.0 ug/dL )

Sub-State Level Maps ( Percent above 2.5 ug/dL | Percent above 5.0 ug/dL | Percent Above 10.0 ug/dL )

Press release

Analysis of multiple-variable missing-not-at-random survey data for child lead surveillance using NHANES [in Statistics in Medicine]

Assessing Child Lead Poisoning Case Ascertainment in the US, 1999-2010 [in Pediatrics]

Lead poisoning is preventable

Lead poisoning and its public health impacts are completely preventable. However, lead-based paint and lead dust remain in millions of older homes in the United States and continue to harm the developing brains of children. Other sources of lead include lead pipes, contaminated soil, and consumer products. While we should not wait until children are poisoned to find and remove hazardous lead from the environment, identifying all lead-exposed children (children with lead in their bodies) is essential to addressing this issue. Our research suggests that, for much of the country, current lead testing practices fall short of that goal.

An incomplete picture of lead poisoning

Commonly cited estimates of lead poisoning in children are based on results of blood tests conducted by medical providers. These estimates are incomplete because lead testing is not required for all children in the U.S., testing guidelines vary by state, and not all states report lead testing data. To assess the scope of the problem, the California Environmental Health Tracking Program (CEHTP), a program of the Public Health Institute, developed a statistical model using data from the National Health and Nutrition Examination Survey (NHANES) to estimate the actual number of lead-exposed children across the U.S. by state.

How many children are falling through the cracks?

To better understand how many lead-poisoned children may have been missed, we compared our estimates of the true number of lead-poisoned children with the numbers of children diagnosed with lead poisoning and reported to the Centers for Disease Control and Prevention (CDC) from 1999-2010. For this particular analysis, lead poisoning was defined as having a blood lead level of 10 ug/dL or higher among children 1-5 years old.

We estimated that 1.2 million children had lead poisoning from 1999-2010. In states that reported data to the CDC during this time, there were 944,000 lead-poisoned children, of whom only 607,000 were identified and reported.

This suggests that:

Our results indicate that:

Frequently Asked Questions