60-Second Science

Even Low Lead Levels Lower IQ

Kids with lead levels within the high end of currently acceptable standards have lower IQ scores than kids with even lower levels. Cynthia Graber reports.














Share on Tumblr

Listen to this Podcast

Toy companies and parents reacted quickly this year when some toys made in China were found to contain lead.  Because lead is known to affect kids’ cognitive development.  In 1991, the Centers for Disease Control set a federal standard of 10 micrograms of lead per deciliter of blood.  So the eight percent of US kids five and younger who have lead levels between 5 and 10 micrograms are considered safe.  But recent Cornell University research in the journal Environmental Health Perspectives supports a stricter standard.   

The research team had previously followed kids from birth through age five. The current study looked again at the children at age six.  The kids were divided into two groups: one with blood lead levels between 0 and 5, and the other with 5 to 10—again, currently considered okay. Turned out that those in the 5-10 group had IQ scores about five points lower than those with the lowest lead levels.  Scientists say this could affect educational performance later in life.  They recommend reconsidering federal standards for lead in consumer products and reevaluating the acceptable blood lead levels in children.

—Cynthia Graber 


Comments

Add Comment
Leave this field empty

Add a Comment

You must sign in or register as a ScientificAmerican.com member to submit a comment.
Click one of the buttons below to register using an existing Social Account.

More from Scientific American

See what we're tweeting about

Scientific American Editors

More »

Free Newsletters


Get the best from Scientific American in your inbox

  SA Digital
  SA Digital

Science Jobs of the Week

Email this Article

Even Low Lead Levels Lower IQ

X
Scientific American Magazine

Subscribe Today

Save 66% off the cover price and get a free gift!

Learn More >>

X

Please Log In

Forgot: Password

X

Account Linking

Welcome, . Do you have an existing ScientificAmerican.com account?

Yes, please link my existing account with for quick, secure access.



Forgot Password?

No, I would like to create a new account with my profile information.

Create Account
X

Report Abuse

Are you sure?

X

Institutional Access

It has been identified that the institution you are trying to access this article from has institutional site license access to Scientific American on nature.com. To access this article in its entirety through site license access, click below.

Site license access
X

Error

X

Share this Article

X