Scientists Say Exposure To A Common Substance Lowered IQs For Half Of America

Well, that sure explains a few things.

By Shawn Paul Wood | Published

This article is more than 2 years old

lead exposure

Do you remember leaded gasoline? If you don’t, odds are your parents might. That’s why it’s called “Unleaded.” After reading a peer-reviewed study in the journal Proceedings of the National Academy of Sciences (PNAS), it is clear why the “un” was made mandatory — lead exposure may have blunted the IQ of at least half of Americans since 1940. That’s close to 170 million people alive today who were “exposed to high-lead levels in early childhood,” and as a result, might be a colossal amount dumber.  

Most of the study focuses on people born before 1996, which is also the year the U.S. Environmental Protection Agency (EPA) banned gas containing lead. The federal government created the Clean Air Act on January 1, 1996, to combat lead exposure. It was the culmination of a 25-year Agency effort to phase out the small amount of lead blended with gasoline used to boost octane levels, which was a practice since the early 1920s.

Lead poisoning—also known as plumbism—can create abdominal pain, nausea, fatigue, irritability, insomnia, or even baby colic. However, this study also shows 50% of all Americans born before 1996 may be a few fries short of a Happy Meal. The study, performed by Florida State University and Duke University, showed that childhood lead exposure cost “America an estimated 824 million points, or 2.6 points per person on average.” That is average because when lead was more common for people born in the 1960s and the 1970s, IQ loss was estimated to be up to six or seven points, primarily from inhaling auto exhaust.

Michael McFarland, an associate professor of sociology at Florida State University and a faculty member of the university’s Center for Demography and Population Health, called the number of people affected by lead exposure “staggering.” He is also the principal study author. “This is important because we often think about lead as an issue for children, and of course it is,” he said. “But what we really wanted to know is what happens to those children who were exposed?”

lead exposure

From leaded gasoline to the toxic water in Flint, Michigan, lead exposure and poisoning seem to have been an ongoing tale of woe in the United States for close to a century. Do you know what else could have created lead exposure in a much smaller case? Action figures and other toys. Think of all the collectible action figures you owned or owned before your mother threw them all away. You’ve probably been mourning about your lost hundreds ever since your parents heard manufacturers painted Star Wars action figures with lead paint. We’re not breaking any news here because other people have considered possible lead exposure with those toys. 

In 2016, New York Attorney General Eric Schneiderman opened an investigation that his office discovered high levels of lead of toys manufactured in China and sold to Toys “R” Us, Kmart, Walmart, and Target over the past few months. (And kids, if you’re not familiar with Kmart or Toys “R” Us, ask your parents.) There were even arts and crafts sets from Cra-Z-Art makers that were found to “contain close to 10 times the amount allowed by federal child safety limits.” In some cases, the toys at the heart of this successful lawsuit contained up to 980 parts per million of lead, while the federal child safety limit is set at 100 parts per million. 

From an upset tummy to kidney disease, lead exposure was no laughing matter and could have hurt some people—or worse. The CDC’s National Center for Environmental Health has valuable information on the subject, so if you are concerned, we recommend reading up on potential lead hazards in toys. However, if you read this, feel a little more ignorant, but want to be sure there is no lead in your house, many eco-activists, including Greenpeace and the EPA, recommend the following actions: 

  • Do not buy painted toys made before 1978 (or get rid of them if they are in your home). 
  • Know where your toys come from because imported painted toys could carry a higher lead risk because lead exposure is less-regulated in developing countries. 
  • If a toy has flaking paint, be cautious or consider removing them from your home.

In the big picture, Dr. McFarland says in the study that a 2-to-3-point IQ difference is nominal. So, it’s not like you’re going to wake up with a case of the Mondays. That notwithstanding, this study on lead exposure shows how sensitive this planet is with the smallest of substances. Humans are even more susceptible to things that we don’t even know. And, by reading this study, we don’t learn more than we thought.