Exposing the Hidden Health Threat of Undiagnosed Childhood Lead Poisoning


Image for Exposing A Hidden Problem through Groundbreaking Research: Lead Poisoning in the United States

A study by PHI’s Tracking California program found that current lead testing practices nationwide may be missing as many as a third of all childhood lead poisoning cases, with most states missing more than half of all childhood lead-poisoning cases. In California, the study led to adoption of new lead testing rules calling for testing of up to 300,000 more children annually.

300K more children who will be tested for lead poisoning following adoption of new California lead testing legislation.

A groundbreaking study in April 2017 by PHI’s California Environmental Health Tracking Program (now called Tracking California) found that current lead testing practices nationwide may be missing as many as a third of all childhood lead poisoning cases. The study found that in some states, more than 80% of lead-poisoned children were unidentified, with the majority of states missing more than half of all childhood lead-poisoning cases.

The study demonstrates that estimates of child lead poisoning based on medical testing data are too low, and that child lead testing practices may not be effective in many states. In California, where just 37% of children with elevated lead levels were identified, the study resulted in successful legislation that strengthened the state’s regulations on lead testing of children. Under the new rules, doctors are required to consider factors that could expose a child to lead, including proximity to lead smelters, freeways or drinking from lead-contaminated plumbing. The California Department of Health estimated that the new rules would lead to an additional 300,000 children being tested for lead annually.

“The numbers of children with lead poisoning we know about are already frighteningly
high—especially since lead poisoning is preventable. But now we know that many more children who have been exposed to lead are not tested, not counted and not treated. Without the true numbers, we can’t help the children who have been poisoned, or root out how and why so many children are being poisoned in the first place.” Eric Roberts, MD, PhD, Tracking California

Commonly cited estimates of lead poisoning in children are based on results of childhood blood tests. But 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 – so the lead poisoning estimates are incomplete. To assess the scope of the problem, Tracking California developed a statistical model using data from national health surveys to determine a more accurate estimate of childhood lead poisoning cases state by state.

The Tracking California researchers found that race and geography are factors in childhood lead poisoning. The study showed that: 

  • Black children are at greatest risk for having high levels of lead in their bodies, compared to other children;
  • Hispanic children are at greatest risk for having any lead in their bodies; 
  • The West and South regions each only found about a quarter of their lead-poisoned children, and the South had the most lead-poisoned children in the U.S.

There is no safe amount of lead in the body, and the chemical can be especially harmful to children’s developing brains. Harmful impacts from lead occur at even the lowest measurable exposures to lead, with studies showing that even low levels of lead exposure can reduce a child’s school performance, educational attainment, and future earning potential. Yet despite these well-known risks from lead exposure, there is no standard guidance for physicians on testing children’s blood lead levels.

Read the press release, see the interactive maps, and find the factsheet, infographic and more.

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