High blood lead levels can cause learning disabilities
13th March 2017 · 0 Comments
By Kari Dequine Harden
Contributing Writer
Is lead poisoning a factor in the achievement gap?
When educators and elected leaders discuss “failing schools,” they talk about poverty, parenting, policy, inequity and the teachers in the classroom.
But there is another factor less discussed but with enormous implications: lead poisoning.
Despite a huge and growing body of research connecting lead poisoning with poor academic performance and behavior issues, it is not a prominent factor in social, education or health policy.
It’s frustrating, said Tulane School of Medicine Professor of Pharmacology Dr. Howard Mielke, who has spent decades studying the connections between lead found in the environment and lead found in the blood of children, and then the connections between lead poisoning and the detrimental individual health and overall societal impacts. Mielke also conducted extensive research during his tenure at the College of Pharmacy at Xavier University, and serves on the board of directors at Lead Safe America Foundation.
The good news – with the exception of a travesty like Flint, Michigan – is that blood lead levels in children nationwide have decreased dramatically over the past 30 years, including in New Orleans. But for many, the damage has already been done, and many are still at risk. There is an increasing amount of research showing that even very low levels of lead can have deleterious effects on the developing brain. The threshold for what is considered a risk has been repeatedly lowered, and there is now consensus that no measurable level of lead should be considered safe.
It doesn’t take much to poison a child, and very young children (under 3 years old) are the most vulnerable, both in their stage of brain development and propensity to put everything in their mouths.
“Lead is an incredibly potent neurotoxin prevalent in older neighborhoods,” writes Research Analyst Michael T. Martin in his 2008 book, A Strange Ignorance: The role of lead poisoning in failing schools.
“It takes a surprisingly small amount of lead to damage developing brains. A few sand-grain sized paint chips will do it. Those children, in turn, will sustain brain damage that ensures both educational and social problems for the rest of their life,” Martin states.
A growing body of medical and psychiatric research links early lead poisoning to a significant drop in I.Q., writes Martin, along with “an inability to learn because brain tissues constructed of lead do not bind properly to form the neural learning connections, attention deficit disorders because lead damaged brain tissues have a tendency to misfire and disrupt normal concentration, violence because the careful balance of brain structures in the prefrontal cortex that inhibits impulsivity and violence are attenuated, and drug use because untreated sufferers find illegal drugs help to medicate the agitation caused by lead damaged brain cells.”
While there is much focus on lead paint found in older neighborhoods where buildings date prior to 1978, (when the U.S. banned the use of lead in household paint despite other Western countries doing so in the 1920’s and 1930’s), Mielke has found soil in New Orleans to also be a significant culprit. Lead as an additive in gasoline was not banned for sale until 1996, and the toxin remains in the air, soil and yards of homes, especially near heavily commuted roadways.
Mielke pointed to Baltimore, where high blood lead levels were found among populations living in buildings made of brick (no lead-based paint). But those buildings were in areas with a significant accumulation of traffic flow.
In the aftermath of Flint, there is also a renewed focus on municipal water supplies – not as easy of a fix as covering contaminated soil or painting a wall, Mielke noted, and one directly instigated by “bean counters” valuing dollars over the health of children.
While New Orleans’ water meets EPA standards, lead is common in the city’s system of pipes, and a recent Louisiana State University School of Public Health survey found that 96 percent of buildings tested had some detectable lead – any of which can be of concern for pregnant women and infants.
LSU Assistant Professor Adrienne Katner is a principal investigator with the Lead Exposure Assessment for Drinking Water Project. She’s been testing water in New Orleans, and has found very concerning levels in some homes, and is continuing to test. But it varies widely house by house, she said.
One of the most challenging parts about lead dust is it is an invisible foe, Mielke said, often microscopic and invisible to the naked eye. “The problem is very fixable, if you can see it.”
The invisibility of the poison in both the literal sense and in the social consciousness was a major frustration for Martin, who observed educators readily blaming children’s learning and behavioral difficulties, or “failing schools,” on teachers, politics, parenting, poverty, race: everything but the well known, prevalent and potent environmental toxin, and in spite of the vast amount of scientific evidence connecting lead poisoning to brain damage.
Having long established a connection between low-income, primarily minority-inhabited neighborhoods and likelihood of elevated blood lead levels, researchers are now narrowing in on the role of lead poisoning in the achievement gap. They are also paying closer attentions to blood lead levels once considered below the threshold for concern.
A 2016 paper by the National Bureau of Economic Research focuses on Rhode Island children born between 1997 and 2005 and asks: “Do low levels of blood lead reduce children’s future test scores?”
Using a vast amount of data, the study tracked test scores alongside Rhode Island’s aggressive lead testing programs and the state’s lead paint remediation programs. The results show “that reductions of lead from even historically low levels have significant positive effects on children’s reading test scores in third grade… Moreover, as we show, poor and minority children are more likely to be exposed to lead, suggesting lead poisoning may be one of the causes of continuing gaps in test scores between disadvantaged and other children.”
Mielke’s numerous studies focus on New Orleans, where he has also found “environmental disparities that translate into health, learning, and behavioral disparities.”
He has mapped New Orleans, both pre and post-Katrina, with markers indicating the median lead levels found in both the children and the environment.
Mielke was part of a study examining pre-Katrina associations between nine soil metals, including lead, and standardized school performance tests. He noted that type of research is much harder now, whereas, prior to the storm, kids primarily attended schools in their own neighborhoods.
The results? “Our analysis shows that standardized test outcomes are significantly related to soil metal conditions of the environment, controlling for important school characteristics such as poverty, racial composition, and teacher-student ratios.”
Where there is lead, there are likely to be other harmful elements, Mielke found.
“The problem is beyond them,” Martin writes of the governing boards of education. “Beyond teacher competence, beyond funding shortages, beyond standards and testing and vouchers and every other ill-conceived rationalization that ignores lead poisoning.”
Martin disputes the notion that, when it comes to lead poisoning, “every child can learn.” He quotes child psychiatrist Dr. Henry Doenlen: “Poor attention spans and impulsive behavior are classic problems associated with lead poisoning, especially if the child can’t seem to learn, no matter how hard he or she tries.”
It’s even more frustrating, Mielke said, because addressing the problem is relatively straightforward and inexpensive, especially given the lifelong costs paid by children, their families and communities.
And in that respect, New Orleans represents a bright spot in continuing to reduce lead levels in the blood of children in urban areas across the nation.
After Hurricane Katrina and the levee failures inundated more than 80 percent of the city, there were predictions that lead levels would skyrocket in the soil, air and blood.
The opposite happened.
According to Mielke’s research, in higher lead level areas of the city, the percentage of children with a median blood level greater than 5 ppb (or micrograms per deciliter) “underwent a remarkable decrease from 64 percent before Katrina to 18.9 percent 10 years post-Karina.”
And the prevailing theories attribute the drop to the covering of much of the city in a fresh layer of sediment, combined with the repainting, rebuilding or renovating of a large percentage of the city’s older homes.
There’s reason for optimism in that decline, and in the effectiveness of paint remediation efforts and adding clean soil. But children in New Orleans are still at risk, and it is now widely accepted there is no safe blood level of lead for children.
As of his 2016 studies, Mielke said there continue to be areas of the city with high lead levels in the soil, and “still too many children are being excessively exposed to lead.”
There is also a “basic lack of understanding on the part of the U.S. population,” Mielke said.
“I’m a scientist and have worked on this issue my whole life,” Mielke said. “But I’m astonished by the lack of appreciation for what the science is all about,” and how that science directly impacts health and societal well-being. “The population is poorly informed.”
Mielke has personal experience. When his daughter showed evidence of lead poisoning, he traced the source to a contaminated outdoor play area at her childcare center. Once addressed, her levels came down, and “she seemed to be able to recover very well.” There is resilience in kids, depending on length and toxicity of exposure, but “we have to know what to do to prevent exposure in the first place.”
Mielke said he’s worried the Trump Administration might allow lead back into gasoline for highway use. Lead is still used in aviation fuel.
And it’s not just paint dust and residual gasoline particles and old pipes and industrial waste that pose risks, especially to children under the age of six years old.
A 2013 study of Mardi Gras beads and other throws from the floats on New Orleans streets found many varieties contained concerning levels of lead.
“These plastic bead products are being used as a dumping ground for old plastic waste, which is loaded with toxic chemicals,” said Jeff Gearhart, principle researcher at the Ecology Center, one of the sponsors of the study. “We estimate that a single year’s inventory of Mardi Gras beads may contain up to 900,000 pounds of hazardous flame retardants and 10,000 pounds of lead.”
Of the beads tested, two-thirds exceeded 100 part per million (ppm) of lead, which is the U.S. Consumer Product Safety Commission (CPSC) federal safety limit for lead in children’s products. (Mardi Gras beads are not classified as a children’s product.) Understandably, it’s not a popular revelation in this town.
Just last month, Mielke tested the kids’ tables and chairs at a New Orleans church. “The chairs were loaded with lead.” Those Chinese-made chairs wouldn’t have even been allowed in the state of California, he said.
Martin’s book also uses the available research to connect lead poisoning to crime, substance abuse, and Attention Deficit Hyperactivity Disorder (ADHD).
Mielke and others have produced vast research showing a startling correlation between the amount of lead pollution in the air when gasoline contained lead, and crime rates in six major U.S. cities, including New Orleans. Because lead poisoning is associated with traits such as impulsivity, aggression, low cognitive IQ, and low self-control, it is associated with the same traits associated with criminality and anti-social behavior.
In Mielke’s 2012 study focusing on aggravated assaults, the correlation between childhood exposure to lead air pollution and crime rates is astounding, and has been found repeatedly in other studies across the globe. Compensating for the passage of time between childhood exposure and adulthood, as lead levels peaked, so did aggravated assaults. As lead levels went down, so did aggravated assaults.
In 1991, a Newsweek article entitled, “Lead and your Kids,” urged the country to take a closer look at lead and learning – a plea still being made by Mielke and Martin and other researchers more than 25 years later. “The new science about lead’s effect on the brain may force policymakers to re-examine some social issues through a new prism,” the Newsweek article stated hopefully. “For example, if lead can cause aggressive behavior, learning disabilities and hyperactivity, might it not also be a contributing factor in poor educational performance among low-income Blacks, who suffer the most lead poisoning?”
So what can you do, as a concerned family member or educator or citizen?
Educate yourself and others on the level of risk in where you live.
Educate yourself and others on basic precautions to reduce chances of exposure.
Basic housekeeping in the form of the removal of outside dust can have a significant impact, as well as removing shoes inside the house; and avoid sanding off old paint.
Pay attention to all the outside areas where children play. Surfaces, such as the side of a house, can act as a collection point, and higher levels are often found in the soil right next to a house, Mielke said.
Buy a water filter, said Katner. One of the simplest and cheapest precautions residents can take is to buy a filter that attaches to the faucet, which starts around $16. Choose a model certified for lead removal by NSF International.
With an unintentional Katrina consequence of new soil and the reduction of old housing stock, New Orleans can represent a “way forward” for the rest of the county, Mielke said.
The benefits in health and societal well-being are immeasurable. And the solution – at least for fixing the soil contamination still prevalent in New Orleans – is as cheap as dirt.
This article originally published in the March 13, 2017 print edition of The Louisiana Weekly newspaper.
