Children more vulnerable to harmful effects of lead

May 4, 2008

Contrary to prevailing assumptions, children are more vulnerable to the harmful effects of lead exposure at the age of 6 than they are in early childhood, according to a Cincinnati Children’s Hospital Medical Center study to be presented May 4 at the annual meeting of the Pediatric Academic Societies in Honolulu.

“Although we typically worry about protecting toddlers from lead exposure, our study shows that parents and pediatricians should be just as, if not more concerned about lead exposure in school-aged children,” says Richard Hornung, Dr.P.H., a researcher in the division of general and community pediatrics at Cincinnati Children’s and the study’s main author.

The researchers found that blood lead concentrations (BPb) at age 6, compared to those at younger ages, are more strongly associated with IQ and reduced volume of gray matter in the prefrontal cortex of the brain, which is involved in planning, complex thinking and moderating behavior.

Overall, the children’s average BPb levels peaked at 13.9 micrograms of lead per deciliter of blood at age 2, then declined to an average of 7.3 micrograms per deciliter by age 6. For children, however, with the same average blood lead levels through age 6, those who received more of their exposure at age 6 had substantially greater decrements in intellectual ability than those more heavily exposed at age 2.

“Lead toxicity is difficult to recognize in a clinical setting, but it can have devastating effects,” says Bruce Lanphear, M.D., director of the Cincinnati Children’s Environmental Health Center and the study’s senior author. “We found that children may be particularly vulnerable to lead exposure just as the child approaches school age, during a period of rapid cognitive development.

Because IQ tests were not administered to children older than 6, it is unknown whether older children are even more vulnerable to environmental lead exposure, according to Dr. Hornung.

Approximately 310,000 U.S. children age 1 to 5 years have blood lead levels greater than 10 micrograms per deciliter, the level at which the Centers for Disease Control and Prevention recommends public health actions be initiated. But research has consistently shown that blood lead levels considerably lower than 10 micrograms per deciliter are associated with adverse effects.

Federal and state regulatory standards have helped to minimize or eliminate the amount of lead in U.S. consumer products and occupational settings, according to the National Institute of Environmental Health Sciences (NIEHS). Today, the most common sources of lead exposure in the United States are lead-based paint in older homes, contaminated soil, household dust, drinking water, lead crystal and lead-glazed pottery.

While extreme lead exposure can cause a variety of neurological disorders, such as lack of muscular coordination, convulsions and coma, lower lead levels have been associated with measurable deficits in children’s mental development and behavioral problems. These include hyperactivity, or ADHD, lowered performance on intelligence tests, and deficits in fine motor function, hand-eye coordination and reaction time. Chronic lead exposure in adults can result in increased blood pressure, decreased fertility, cataracts, nerve disorders, muscle and joint pain as well as problems with memory or concentration.

Source: Cincinnati Children's Hospital Medical Center

Explore further: Researchers find evidence of DNA damage in veterans with Gulf War illness

Related Stories

Researchers find evidence of DNA damage in veterans with Gulf War illness

October 19, 2017
Researchers say they have found the "first direct biological evidence" of damage in veterans with Gulf War illness to DNA within cellular structures that produce energy in the body.

IDSA Infectious Diarrhea guidelines recommend when to test, when to treat

October 19, 2017
New culture-independent tests are much more sensitive than traditional diagnostic methods in detecting the cause of infectious diarrhea, a significant problem that leads to nearly 500,000 hospitalizations and more than 5,000 ...

Teenage girls more likely to self-harm than boys

October 18, 2017
There has been a sharp rise in self-harm reported in general practices for girls aged between 13-16 years from 2011 to 2014, compared with boys of the same age. In socially deprived areas, referrals to mental health specialist ...

HIV infection, even with antiretroviral therapy, appears to damage a growing child's brain

October 17, 2017
HIV infection alters brain development in young children, even when they receive antiretroviral treatment early in life, shows a report in Frontiers in Neuroanatomy. Children exposed to, but not infected by, HIV also appear ...

Who's most at risk of head injury in youth football?

October 17, 2017
(HealthDay)—Young football players are more likely to experience a brain-jarring hit to the head if they're part of a team's running and passing game or a fast-moving defender, a small study found.

National roll-out of PrEP HIV prevention drug would be cost-effective

October 18, 2017
Providing pre-exposure prophylaxis (PrEP) medication to men who have sex with men who are at high risk of HIV infection (equivalent to less than 5% of men who have sex with men at any point in time) in England would be cost-effective, ...

Recommended for you

Three million Americans carry loaded handguns daily, study finds

October 19, 2017
An estimated 3 million adult American handgun owners carry a firearm loaded and on their person on a daily basis, and 9 million do so on a monthly basis, new research indicates. The vast majority cited protection as their ...

More teens than ever aren't getting enough sleep

October 19, 2017
If you're a young person who can't seem to get enough sleep, you're not alone: A new study led by San Diego State University Professor of Psychology Jean Twenge finds that adolescents today are sleeping fewer hours per night ...

Across Asia, liver cancer is linked to herbal remedies: study

October 18, 2017
Researchers have uncovered widespread evidence of a link between traditional Chinese herbal remedies and liver cancer across Asia, a study said Wednesday.

Eating better throughout adult years improves physical fitness in old age, suggests study

October 18, 2017
People who have a healthier diet throughout their adult lives are more likely to be stronger and fitter in older age than those who don't, according to a new study led by the University of Southampton.

Global calcium consumption appears low, especially in Asia

October 18, 2017
Daily calcium intake among adults appears to vary quite widely around the world in distinct regional patterns, according to a new systematic review of research data ahead of World Osteoporosis Day on Friday, Oct. 20.

New study: Nearly half of US medical care comes from emergency rooms

October 17, 2017
Nearly half of all US medical care is delivered by emergency departments, according to a new study by researchers at the University of Maryland School of Medicine (UMSOM). And in recent years, the percentage of care delivered ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.