In kids, even low lead levels can cause lasting harm
In a recent unpublished analysis using integrated data from multiple sources, we found that fully 35 percent of children in a sample of preschool classrooms had an elevated blood lead level at some point in their lives.
The treatment options for children with elevated blood lead levels include dietary approaches and dealing with the effects of lead by managing sensory exposures. At greater exposures, chelation therapy — in which a synthetic compound is injected into the bloodstream which binds itself to the heavy metals — can be used. Though chelation has been shown to significantly reduce blood lead levels in the short term, there is evidence of a rebound in lead levels after therapy has concluded. Also, blood lead levels do not fully capture the retention of lead in bone and deep tissue.
Long-term consequences
Children exposed to lead are at elevated risk for learning delays and academic issues. We have also found that students with confirmed early childhood lead exposure have lower kindergarten readiness scores.
In tracking the experiences of children in our community, we find that lead-exposed children entering high-quality preschool start the year significantly behind their nonexposed peers.
In our ongoing research, we have found that on standardized measures these children score 10-30 percent below their peers on skills such as identifying letters, numbers and shapes. More sobering is the reality that while these children show significant progress during preschool they still finish the year, on average, below where their nonexposed peers start the preschool year.
This disparity is likely to grow as children age unless special efforts are made to address it. Results from Detroit show that these children are much more likely to experience academic challenges as they age.
And it looks like it doesn’t take much lead to cause harm. Other research has shown that blood levels well below the current standard for intervention can also cause negative effects on school readiness for young children.
There is no known safe level of lead exposure
Until a few years ago, the federal standard for action was 10 micrograms per deciliter of blood, and in 2012 it was lowered by half in recognition of evidence showing a lower threshold of concern.
But the truth is there is no known safe level of blood lead for children, and the American Academy of Pediatrics and the Centers for Disease Control and Prevention have said as much.
The medical research community has documented negative impacts on children with even lower levels of lead exposure than the current 5 micrograms per deciliters standard. With that view, we might consider every child with a confirmed nonzero lead test as at-risk.
Based on our analysis of lead data in our county, we calculate that if this standard were adopted in the U.S., our lead exposure rate for kids younger than 6 in a single year would climb from 9 percent to 3-4 times this rate.
Short of ensuring that every housing structure has been certified as lead-safe, parents and caregivers should be the first line of defense in keeping children from this exposure. Testing lead blood levels in children is simply too late.
This is akin to the TSA searching for lethal weapons after the passengers have boarded the flight and the plan has taken off. Once the lead is in the bloodstream, the damage is real and lasting for these children, and the options for response are far fewer and less effective.
Robert L. Fischer is Co-Director of the Center on Urban Poverty and Community Development, Case Western Reserve University. Elizabeth Anthony is Research Assistant Professor, Center on Urban Poverty and Community Development, Case Western Reserve University. This article is published courtesy of The Conversation (under Creative Commons-Attribution/No derivative).
