New study suggests brain damage from lead exposure can be limited with early action
The best way to keep a child safe from lead poisoning is to prevent them from being exposed in the first place.
But that's not always possible, particularly in Milwaukee, a city with an aging housing stock.
Even though city officials have taken steps to remove lead hazards — including a recent plan to spend more than $20 million in federal pandemic relief on the effort — more than 1,000 children tested last year had elevated lead levels in their blood.
Now, researchers are finding new ways to help those children
“What do we do with the millions of kids who have already been poisoned?” asked Dr. Jay Schneider, a professor at Thomas Jefferson University who studies the interactions of behavior and molecular neuroscience.
In Milwaukee, 1,065 children, about 5.6% of those who were tested, were found to have five or more micrograms per deciliter of lead in their blood in 2021, according to figures provided by Milwaukee Health Department spokeswoman Emily Tau.
Lead is now well-known as a neurotoxin, causing damage that is especially harmful to developing brains. Behavioral problems, poor impulse control, IQ deficits and calcium deficiencies, among other problems have all been linked to the heavy metal. Lead-poisoned children also tend to have worse educational outcomes when compared to their lead-free peers.
Schneider said his research suggests those children can overcome some of that cognitive impairment by activating other parts of the brain through an enriched social and physical environment. In children, that could look like encouraging play, regularly introducing new toys and reading to them.
Schneider's theory came from a study of lead-poisoned rats who regained memory functions damaged by lead after receiving early doses of social interaction and environmental enrichment.
Other experts are cautious about claims that early childhood education can have a large effect on lead-poisoned children.
Ruth Ann Norton, the president and chief executive of the Green & Healthy Homes Initiative and a national expert on safe housing, pointed out most studies have found only marginal improvements from the impact of early intervention in such cases.
That fact also was acknowledged by the Centers for Disease Control and Prevention, which released a 2015 report stating, in part, “No studies specifically examine the impact of early childhood educational interventions on cognitive or behavioral outcomes for children who have been exposed to lead.”
How the lead exposure study was done and what it showed
In the study, Schneider exposed rats to the same levels of lead for the first three weeks of their lives and tested their memory.
The lead exposure was shown to damage memory, a function of the brain controlled by hippocampus, significantly changing roughly 3,500 genes in the rats.
Then Schneider placed one group in an enriched environment full of toys, climbing and nesting materials and regularly introduced new tunnels. The other group was placed in a cage identical in size but without any of those items.
He then retested the rats to study the environment’s impact on memory.
Schneider said the rats from the nonenriched environment continued to have the same, or worsening memory issues, while the rats from the enriched environment did not have memory problems.
“By day two of memory testing, the distance between the two groups had become significant and remained significant at 10 days,” Schneider said.
Moreover, among the rats living in the enriched environment, he said he found 80% of the genes that were initially damaged had reversed the damage.
But Schneider also was cautious, saying he does not think the same changes in gene expression will happen in humans, since lead damage is irreversible.
He said policyholders should still focus on preventing children from being poisoned in the first place.
Damage from lead is not reversible, but its effects could be blunted with the right strategies
Schneider said the impact of early environmental factors on the hippocampus has larger implications for the brain.
“The assumption is, if this is happening in the hippocampus, it would be unusual that it wouldn’t also be happening in other parts of the brain, the prefrontal cortex, for example,” he said.
The prefrontal cortex is one of the most important parts of the brain, responsible for many of the functions lead-poisoned children struggle with, such as abstract thinking, impulse control, sustained attention and motor functions.
“If you have a stroke, and part of it has been damaged by that stroke, with the right intervention, different parts of the brain can take on tasks from the damaged part of the brain,” Schneider said, adding the same phenomena could happen with lead-poisoned brains.
“Under the right circumstances, you might be able to take advantage of the fact that, in particular, young brains have a tremendous capacity of plasticity.”
Schneider believes his research means children already suffering from lead poisoning may not be destined to experience the negative outcomes associated with it and that parents — and society — should keep pushing lead-poisoned children to achievements beyond low expectations.
“I think we need to have community-level interventions (in) caregiving, enriching the environment of the child (and) providing early preschool intervention,” he said. “By providing these types of stimulatory interventions at an early age, we might be able to help overcome some of the issues they’re going to have.“
Need resources about lead?
Visit this general guide about lead
Read the Q&A of Dr. Veneshia McKinney-Whitson
Need more help with lead questions? The Milwaukee Resource Guide is here to help. Have something you want answered? Submit a question.
Talis Shelbourne is an investigative solutions reporter covering the issues of affordable housing, environment and equity issues. Have a tip? You can reach Talis at (414) 403-6651 or tshelbourn@jrn.com. Follow her on Twitter at @talisseer and message her on Facebook at @talisseer.
This article originally appeared on Milwaukee Journal Sentinel: Early intervention may help improve the recovery of lead-poisoned kids
