Andy’s Quick Hits (180): Lead exposure shrank IQ of half of Americans

Lead in petrol, gasoline, is a thing of the past. Finally banned in 1996 in the USA and earlier in most European countries. However, a recent study out of Duke University shows that the impact of lead exposure to those who were exposed is dramatic. Very dramatic.

A reminder that lead is neurotoxic and can destroy brain cells if it enters the body and cause multiple cognitive disruptions. Children are particularly susceptible to this. Therefore, those who grew up during in the 1960s and 70s in the USA had potentially the highest exposure. The authors used multiple population data sets and calculated that in 2015 more than 170 million Americans had clinically concerning levels of lead in their blood when they were children.

This will have put them at risk of lower IQ, but also multiple other risks such as, reduced brain size, and greater risk of mental illness in adulthood. The authors calculated that this had an impact equivalent to 6 IQ points averaging to 3 points across the whole populations. These are dramatic sizes able to push an individual over a threshold but across a population having a 6% decrease in IQ is very worrying — not to mention the other long-term health consequences.

Reference:
Michael J. McFarland, Matt E. Hauer, Aaron Reuben.
Half of US population…