New Study: Half of U.S. Adults Exposed to Harmful Lead Levels as Kids
FILE – This Sept. 13, 1979, file photo shows motorists as downtown parking lots fill up in Los Angeles. Over 170 million of people born in the United States who were adults in 2015 were exposed to harmful levels of lead as children, according to a study published in the Proceedings of the National Academy of Sciences on Monday, March 7, 2022. The researchers looked only at lead exposure caused by leaded gasoline, the dominant form of lead exposure from the 1940s to the late 1980s, according to data from the U.S. Geological Survey. (AP Photo/Wally Fong, File)
Over 170 million U.S.-born people who were adults in 2015 were exposed to harmful lead levels as children, a new study estimates.
And the study revealed that exposure to harmful lead levels resulted in a drop in IQ.
Researchers used blood-lead level, census and leaded gasoline consumption data to examine how widespread early childhood harmful lead levels exposure was in the country between 1940 and 2015.
In a paper published in the Proceedings of the National Academy of Sciences on Monday, they estimated that half the U.S. adult population in 2015 had been exposed to lead levels surpassing five micrograms per deciliter — the Centers for Disease Control and Prevention threshold for harmful lead exposure at the time.
In studying harmful lead levels, the scientists from Florida State University and Duke University also found that 90% of children born in the U.S. between 1950 and 1981 had blood-lead levels higher than the CDC threshold.
The researchers found significant impact on cognitive development: on average, early childhood exposure to lead resulted in a 2.6-point drop in IQ.
The researchers only examined lead exposure caused by leaded gasoline, the dominant form of exposure from the 1940s to the late 1980s, according to data from the U.S. Geological Survey. Leaded gasoline for on-road vehicles was phased out starting in the 1970s, then finally banned in 1996.
Study lead author Michael McFarland, an associate professor of sociology at Florida State University, said the findings were “infuriating” because it was long known that lead exposure was harmful, based on anecdotal evidence of lead’s health impacts throughout history.
Though the U.S. has implemented tougher regulations to protect Americans from lead poisoning in recent decades, the public health impacts of exposure could last for several decades, experts told the Associated Press.
“Childhood lead exposure is not just here and now. It’s going to impact your lifelong health,” said Abheet Solomon, a senior program manager at the United Nations Children’s Fund.
Early childhood exposure to harmful lead levels is known to have many impacts on cognitive development, but it also increases risk for developing hypertension and heart disease, experts said.
“I think the connection to IQ is larger than we thought and it’s startlingly large,” said Ted Schwaba, a researcher at University of Texas-Austin who studies personality psychology and was not part of the new study.
Schwaba said the study’s use of an average to represent the cognitive impacts of lead exposure could result in an overestimation of impacts on some people and underestimation in others.
Previous research on the relationship between lead exposure and IQ found a similar impact, though over a shorter study period.
Bruce Lanphear, a health sciences professor at Simon Fraser University in Vancouver who has researched lead exposure and IQ, said his 2005 study found the initial exposure to lead was the most harmful when it comes to loss of cognitive ability as measured by IQ.
“The more tragic part is that we keep making the same … mistakes again,” Lanphear said. “First it was lead, then it was air pollution. … Now it’s PFAS chemicals and phthalates (chemicals used to make plastics more durable). And it keeps going on and on.
“And we can’t stop long enough to ask ourselves should we be regulating chemicals differently,” he said.
Source: Associated Press, “Half of US adults exposed to harmful lead levels as kids,” by Drew Costley, Mar. 7, 2022.
Take action to improve your safety culture and eliminate human errors in healthcare
TapRooT® Root Cause Analysis has a team of investigators and instructors who have years of extensive training ready to offer assistance worldwide.
We also offer ongoing support to our clients through free newsletters and root cause tip videos, the root cause analysis blog, and our annual Global TapRooT® Summit We’re here to find solutions for you.
TapRooT® is global to meet your needs
See our full selection of courses.
Want to discuss a course? Please reach out to discover what we can do for you, or call us at 865.539.2139.
Need an on-site course? contact us or call: MAIN: 865.539.2139; SUPPORT: 865.357.0080.
A do-not-miss opportunity: The 2022 Global TapRooT® Summit
Bring your team(s) to the 2022 Global TapRooT® Summit in Knoxville, Tennessee.
Pre-Summit courses are May 2-3 and the Summit with incredible keynote speakers and sessions is May 4-6.
Check out the Summit brochure for all the details.
Register your team(s) today for the 2022 Global TapRooT® Summit — a unique gathering of industry leaders, professionals, TapRooT® instructors, and folks who want to learn how to work safer and smarter.