Petrol, pipes, paint: they made a whole generation duller. That’s if you believe the research on the effects of lead on IQ. By interfering with neurological development, the lead that we used to encounter routinely has left hundreds of millions of us with a tiny bit of brain damage.

In this episode of The Studies Show, Tom and Stuart look at the toxic effects of lead - from very obvious, high-dose lead poisoning to the more insidious, low-level effects that have apparently held millions of people back. How strong is the evidence for the effects of low-level lead exposure on IQ?

The Studies Show is brought to you by Works in Progress magazine, a journal of ideas to accelerate human progress. If you’re a student aged 18-22 and want to attend the Works in Progress “Invisible College” this August (at which Stuart is speaking), take a look at this link.

Show Notes

* Centers for Disease Control (CDC) page on lead poisoning

* Articles on the history of lead poisoning from the BBC and the Guardian

* 2022 PNAS study concluding that “half of US population exposed to adverse lead levels in early childhood” (the one with the “824,097,690” figure)

* Article on blood lead levels and which are considered dangerous

* The 2005 meta-analysis on lead and children’s IQs

* Cited in the 2021 “Global Lead Exposure Report”

* The critique from the CDC in 2007

* The critique paper from 2013

* The critique paper from 2016

* The correction from 2019

* The critique paper from 2020

* Quasi experiments: from Rhode Island; using manufacturing employment

* 2018 paper on low-level lead and all-cause mortality

Credits

The Studies Show is produced by Julian Mayers at Yada Yada Productions.