Lead in Topsoil Produces Kids With Cognitive Problems

A new study out of Carnegie-Mellon examines the effect of topsoil lead contamination on cognitive problems among toddlers. To start, the authors construct a map of large US counties showing which ones are above and below average in lead contamination:

The green counties have a topsoil lead concentration of about 10 ppm, while the red counties have a concentration of about 20 ppm. The results of the study are simple:

  • Overall, about 3.5 percent of boys report cognitive difficulties.
  • In counties with high lead concentrations, this increases to 7.5 percent.
  • In urban areas with high lead concentrations, it increases to 11 percent.

Consistent with previous studies, the effects on girls are much smaller (though still positive).

The reason I’m highlighting this study is not because it shows that lead poisoning affects cognitive ability. That’s well-known and uncontroversial. However, it also shows specifically that lead in topsoil is a significant factor in producing those cognitive problems. And if topsoil lead affects cognitive ability, then topsoil lead also affects the likelihood of being prone to violent crime later in life. I’ve been banging the drum of topsoil lead for a while—it’s almost certainly a bigger problem than lead in drinking water—and this study is yet another that confirms it’s a serious problem.

Topsoil remediation is eminently achievable. In Norway, they’ve been doing it for years with a goal of zero lead in topsoil. But it’s obviously a big, expensive job. It’s too bad we no longer have leadership in this country that cares about such things.

FOLLOW THE MONEY

Corporations and billionaires don’t fund journalism like ours that exists to shake things up. Instead, support from readers allows Mother Jones to call it like it is without fear, favor, or false equivalence.

And right now, a longtime friend of Mother Jones has pledged an incredibly generous gift to inspire—and double—giving from online readers. That's huge! Because you can see that our fall fundraising drive is well behind the $325,000 we need to raise. So if you agree that in-depth, fiercely independent journalism matters right now, please support our work and help us raise the money it takes to keep Mother Jones charging hard. Your gift, and all online donations up to $94,000 total, will be matched and go twice as far—but only until the November 9 deadline.

$400,000 to go: Please help us pick up the pace!

payment methods

FOLLOW THE MONEY

Corporations and billionaires don’t fund journalism like ours that exists to shake things up. Instead, support from readers allows Mother Jones to call it like it is without fear, favor, or false equivalence.

And right now, a longtime friend of Mother Jones has pledged an incredibly generous gift to inspire—and double—giving from online readers. That's huge! Because you can see that our fall fundraising drive is well behind the $325,000 we need to raise. So if you agree that in-depth, fiercely independent journalism matters right now, please support our work and help us raise the money it takes to keep Mother Jones charging hard. Your gift, and all online donations up $94,000 total, will be matched and go twice as far—but only until the November 9 deadline.

$400,000 to go: Please help us pick up the pace!

payment methods

We Recommend

Latest

Sign up for our free newsletter

Subscribe to the Mother Jones Daily to have our top stories delivered directly to your inbox.

Get our award-winning magazine

Save big on a full year of investigations, ideas, and insights.

Subscribe

Support our journalism

Help Mother Jones' reporters dig deep with a tax-deductible donation.

Donate