EXPOSURE to lead may have caused a drop in IQ levels in millions of Americans, a new study says.
In 1923, leaded gasoline was introduced to vehicles as a way to keep engines functional – by 1996, it was banned by the Clean Air Act.
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Now, a new study asserts that more than 170 million Americans alive today were exposed to high levels of lead from car exhaust in early childhood.
Using publically available data, the study’s authors calculate that as of 2015, lead exposure robbed more than 824 million IQ points from nearly half of the American population.
While Americans who were children in the 1960s and 1970s are of greatest concern, those born before 1996 may also be at a huge risk for lead-related health issues, which include neurodegenerative disease.
Mental illness, cardiovascular issues, kidney damage, and anemia are other health concerns that can appear after breathing in, ingesting, or absorbing lead for a long period of time.
The research, led by a Duke University Ph.D. candidate and two professors of sociology from Florida State University, was published in the journal Proceedings of the National Academy of Sciences.
Lead, classified as a developmental neurotoxicant, is not safe to consume at any point in life as it can easily destroy brain cells once it has entered a person’s system, according to a report by Duke University.
However, it is especially detrimental to children as it can hinder brain development, leading to permanent cognitive and behavioral issues.
“Lead is able to reach the bloodstream once it’s inhaled as dust, or ingested, or consumed in water,” Aaron Reuben, a PhD candidate in clinical psychology at Duke University and one of the study’s authors, said.
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“In the bloodstream, it’s able to pass into the brain through the blood-brain barrier, which is quite good at keeping a lot of toxicants and pathogens out of the brain, but not all of them,” Reuben added.
On top of the serious long-term health issues, lead can also take a huge toll on one’s intelligence, Reuben and study co-authors Michael McFarland and Mathew Hauer noted.
Exposure to lead can potentially shift people’s IQ from a below-average ranking (IQ score less than 85) to a ranking on par with having an intellectual disability (or an IQ score below 70).
In the future, the researchers want to examine the long-term implications of lead exposure and how it may have affected minority communities.
“Millions of us are walking around with a history of lead exposure,” Reuben said.
“It’s not like you got into a car accident and had a rotator cuff tear that heals and then you’re fine. It appears to be an insult carried in the body in different ways that we’re still trying to understand but that can have implications for life,” he added.
