More than half of American adults now have slightly lower IQs because for many years, when they were children in the 20th century, they inhaled the exhaust of cars that ran on leaded gasoline, according to a new american scientific studywhose estimates were described as “shocking” by the researchers.
Leaded gasoline used during the last century – before it was eventually phased out for the sake of unleaded – is estimated to have “stolen” a total of 824 million IQs from about half of Americans. This equates to an average reduction of the average American IQ by almost three IQs.
In fact, those born between the mid-1960s and the early 1970s – the busiest period in terms of exposure to gasoline lead – may have lost six to seven IQs each. The researchers pointed out that a few IQs may seem insignificant, but they may be enough to drop a person below average intelligence (IQ less than 85) or even worse to characterize a person as mentally retarded (IQ below 70). ).
Lead was added to gasoline in 1923 to make the car’s engine work better. But the “health” of the vehicles came at the expense of the health of the people, who were exposed for years to lead gases from the exhaust.
Researchers at Duke University in North Carolina and Florida, led by Aaron Robben, who published in the journal National Academy of Sciences (PNAS), calculated in the long run the burden on the health of each An American who was alive in 2015.
It was estimated that at least 170 million Americans that year – more than half the US population – had alarmingly high levels of lead in their blood as children, which may have resulted in lower IQs as well as lower brain volume, a greater chance of mental illness and increased cardiovascular risk as adults.
Consumption of leaded gasoline increased significantly in the early 1960s and peaked in the 1970s. Virtually anyone born in those two decades, according to researchers, was exposed to dangerous levels of lead in the environment because of cars.
Lead is neurotoxic and can damage brain cells once it enters the body. According to experts, there is no safe level of exposure to lead at any stage of human life. Young children in particular are vulnerable to the ability of lead to disrupt brain development and consequently to undermine cognitive ability.
“Lead is able to enter the bloodstream from the moment it is inhaled as a powder or swallowed or consumed with water. “Through the blood it can penetrate the blood-brain barrier,” said Reuben.
More than 70 years of leaded gasoline use have left a lasting mark on human health and intelligence, according to the study. It remains to be seen whether long-term exposure to lead in the past may accelerate aging or cognitive impairment – or even dementia – in the elderly.
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