Oregon Health and Science University researcher Joel Nigg has reported that virtually all US children have measurable levels of lead in their bodies.
Lead is a neurotoxin. The EPA now says that there is “no demonstrated safe concentration of lead in blood.” Childhood lead exposure at nearly any level can seriously and permanently reduce IQ. Even levels under 10 μg/dL (milligrams/deciliter) can reduce IQ by as much as seven points.
While government regulation drastically reduced environmental lead a generation ago by regulating automobile fuel and paint, it’s still found in trace amounts in everything from children’s costume jewelry to imported candies to soil and drinking water.
Dr. Nigg suggests there’s a correlation between lead exposure and ADHD. Two studies have found that the children with the disorder have higher levels of lead in their blood. Lead attaches itself selectively to sites in the brain’s frontal cortex and striatum. There, it acts on gene-expression and disrupts brain activity, brain development or both.
A team of researchers at the University of Cincinnati has been following a group of 300 children for more than 30 years and recently performed a series of MRI scans that highlighted the neurological differences between subjects who had high and low exposure to lead during early childhood. They found network connections within the brain become both slower and less coordinated.
Another study found that high exposure to lead during childhood was linked to a permanent loss of gray matter in the pre-frontal cortex, the executive function center controlling emotional regulation, impulse control, attention, verbal reasoning, and mental flexibility. The neurological impact turns out to be greater among boys than girls.
While our cars run on lead-free fuel today, they spent more than 50 years spewing lead from their tailpipes, and all that lead has settled permanently into the soil that we walk on, grow our food in, and let our kids play around.
Lead in soil doesn’t stay in the soil. As the weather dries up, the lead gets kicked back into the atmosphere in a process called resuspension. People and pets track lead dust from soil into houses, where it’s ingested by small children via hand-to-mouth contact. The same for lead dust generated by old paint inside houses.
In the 2014 documentary “MisLEAD: America’s Secret Epidemic,” Dr. John Rosen of Montefiore Medical Center holds tiny flakes of lead paint, the size of grains of sand, on the end of his pointer finger. “This amount of contaminated household dust with lead-based paint in it will cause childhood lead poisoning,” he said. “It takes very little.”
The documentary’s director visited her child’s school to demonstrate a lead measuring device. A student had a pink crystal barrette in her hair. It tested 80,000 parts per million lead. The girl said she always chewed on the end of it when she was taking tests. Federal guidelines dictate children’s jewelry cannot contain lead content exceeding 100 parts per million. Lead is also found in sparkly, pink lip gloss from China used by girls. Most lipsticks contain at least a trace of lead. In 2011 the FDA found traces of lead in 400 different lipsticks.