Leaded Gas Likely Dealt Severe Blow to US Population's IQ, Study Warns

The study’s lead author told media he was “shocked” by their findings, and is “still shocked” despite being prepared for it when he looks at the numbers in question.

A new study conducted by researchers from Florida State University and Duke University sheds light on the use of leaded gasoline in the United States – banned since 1996 – and it likely causing significant IQ losses in the country’s population.

The authors of the study published in the Proceedings of the National Academy of Sciences this week estimate that “170 million Americans alive today were exposed to high-lead levels in early childhood,” and that lead is “responsible for the loss of 824,097,690 IQ points” in the US population as of 2015.

“I frankly was shocked,” study’s lead author Michael McFarland, professor of sociology at Florida State University, told USA Today. “And when I look at the numbers, I’m still shocked even though I’m prepared for it.”

The researchers warned that anyone in the US who was born before the ban on leaded gas in 1996 may have suffered “the cognitive consequences of lead exposure,” and that, at its worst, those who were born in the 1960s and in the 1970s – the time of the peak use of leaded gas – may have lost up to seven points of IQ, the media outlet notes.

Aaron Reuben, the study’s co-author and doctoral candidate in clinical psychology at Duke University, also said that lead is still used in aviation fuel for some aircraft.

And Hannes Schwandt, professor at Northwestern University and expert in human development and social policy who wasn’t involved in the study, reportedly said that “children in vulnerable communities who live near busy streets and highways” are more likely to be exposed to lead.