Researchers estimate that childhood exposure to automobile exhaust from leaded gasoline cost about 170 million Americans, or more than half of the population of the United States, 824 million IQ points.
Lead was originally added to gasoline in 1923 to aid in the maintenance of automobile engines. However, the health of our automobiles came at the price of our own health and well-being.
According to a recent research, childhood exposure to automobile exhaust from leaded gasoline cost more than 170 million Americans, or over half the population of the United States, 824 million IQ points.
According to the results of Aaron Reuben, a PhD candidate in clinical psychology at Duke University, and colleagues at Florida State University, Americans born before 1996 may now be at a higher risk for lead-related health concerns, such as brain aging. Although leaded gasoline for automobiles was outlawed in the United States in 1996, the researchers claim that everyone born before the end of that period, particularly those born at the height of its usage in the 1960s and 1970s, experienced alarmingly high lead exposures as youngsters.
The team’s study was published in the journal Proceedings of the National Academy of Sciences the week of March 7.
Lead is neurotoxic, and once it enters the body, it may damage brain cells. As a result, health experts warn there is no such thing as a safe amount of exposure at any time in life. Lead’s tendency to disrupt brain growth and diminish cognitive capacity makes young children particularly susceptible. Unfortunately, our brains, regardless of age, are ill-equipped to hold it at away.
“When lead is breathed as dust, swallowed, or absorbed in water, it may enter the bloodstream,” Reuben said. “It can flow into the brain across the blood-brain barrier, which keeps a lot of toxicants and pathogens out of the brain, but not all of them,” says the researcher.
Automotive exhaust was one of the most common ways for lead to enter people’s bloodstreams.
Reuben and his co-authors Michael McFarland and Mathew Hauer, both professors of sociology at Florida State University, used a very straightforward technique to solve the complicated topic of how leaded gas consumption for more than 70 years may have left a lasting effect on human health.
They calculated the potential lifetime burden of lead exposure borne by every American living in 2015 using publicly accessible data on childhood blood-lead levels, leaded-gas usage, and demographic statistics. They calculated IQ points lost from leaded gas exposure as a proxy for its negative influence on public health using this data to evaluate lead’s attack on human intellect.
The findings astounded the researchers
“I was stunned,” McFarland said. “And even though I expected it, I’m still surprised when I look at the stats.”
More than 170 million Americans (more than half of the population) had clinically concerning levels of lead in their blood as children as of 2015, putting them at risk for other long-term health impairments such as reduced brain size, increased mental illness, and increased cardiovascular disease in adulthood.
The use of leaded gasoline skyrocketed in the early 1960s and peaked in the 1970s. As a consequence, Reuben and his colleagues discovered that almost everyone born during those two decades was almost certainly exposed to harmful amounts of lead from automobile exhaust.
Even more shocking was lead’s impact on intelligence: it’s estimated that childhood lead exposure reduced America’s cumulative IQ score by 824 million points, or about three points per person on average. People born in the mid-to-late 1960s may have lost up to six IQ points at worst, according to the researchers, while youngsters with the highest levels of lead in their blood, eight times the current minimal threshold to cause clinical concern, may have lost more than seven IQ points on average.
Although a few IQ points may seem insignificant, the authors point out that these changes are significant enough to push those with below-average cognitive capacity (IQ score less than 85) into the category of intellectual impairment (IQ score below 70).
McFarland is now examining the racial differences in childhood lead exposure with the hopes of highlighting the health inequities experienced by Black children, who were exposed to lead more often and in higher amounts than white children.
Based on prior results that individuals with high childhood lead exposure may have accelerated brain aging, Reuben’s next step will be to investigate the long-term effects of past lead exposure on brain health in old age.
Reuben said, “Millions of us are going around with a history of lead exposure.” “It’s not like you were in a car accident and tore your rotator cuff, which subsequently healed and you were OK. It looks to be an insult carried throughout the body in many ways that we’re still trying to figure out, but that has life-threatening consequences.”
