Even minute levels of lead cause brain damage in children

The study examined the effect of lead exposure on cognitive function in children whose blood-lead levels (BLLs) were below the Centers for Disease Control and Prevention (CDC) standard of 10 micrograms per deciliter (mcg/dl) -- about 100 parts per billion. The researchers compared children whose BLLs were between 0 and 5 mcg/dl with children in the 5-10 mcg/dl range.

"Even after taking into consideration family and environmental factors known to affect a child's cognitive performance, blood lead played a significant role in predicting nonverbal IQ scores," says Richard Canfield, a senior researcher in Cornell's Division of Nutritional Sciences and senior author of the study in the journal Environmental Health Perspectives. "We found that the average IQ scores of children with BLLs of only 5 to 10 mcg/dl were about 5 points lower than the IQ scores of children with BLLs less than 5 mcg/dl. This indicates an adverse effect on children who have a BLL substantially below the CDC standard, suggesting the need for more stringent regulations," he said.

In the United States over the last several months, nearly 50 specific products, including millions of toys for young children, have been recalled due to excessive lead in the paint, plastics and metal. "Our findings emphasize the very real dangers associated with low-level exposures, to which lead in toys can contribute," Canfield said.

U.S. children are exposed to lead primarily from household dust contaminated by deteriorating interior lead-based paint. In addition to toys, other potential sources include contaminated soil, imported food stored in lead-glazed pottery and certain plastic, metallic and painted products.

This most recent finding builds on the same research team's influential 2003 study, published in the New England Journal of Medicine, that reported adverse effects of BLLs below 10 mcg/dl in a group of children followed from infancy to age 5. "Our new findings are based on follow-up testing of the same children at age 6, using a more comprehensive IQ test to assess cognitive function. The results provide compelling evidence that low-level lead exposure has effects into the school-age years," said Todd Jusko '01, a University of Washington Ph.D. candidate in epidemiology and co-author on both reports.

"Children living in poverty disproportionately suffer from elevated BLLs," said statistician and co-author Charles Henderson, a Cornell senior researcher in human development. He also noted that "even a small decline in an IQ score is likely to be reflected in aptitude test scores such as the SAT."

According to the CDC, about one out of every 50 children in the United States between ages 1 and 5 has a BLL above 10 mcg/dl and about 10 percent of children have BLLs of 5 mcg/dl or higher; about 25 percent of U.S. homes with children under age 6 have a lead-based paint hazard.

"The bottom line," according to Canfield, "is that lead is a persistent neurotoxin that causes brain damage. The fact that lead has been found in millions of toys, even toys specifically designed for children to put into their mouths, presents an unacceptable risk. Our findings suggest the need to re-evaluate the current federal standards for lead in consumer products and the current definition of an elevated BLL in children."

Source: Cornell University

China vows overhaul of 'chaotic' milk industry
(AP) -- China's Cabinet vowed a complete overhaul of the scandal-ridden dairy industry Monday, pledging to inspect every link from the farm to the dinner table to try to restore public trust in Chinese-made food products.
Battling cancer, one cell at a time
New research suggests that the identification and examination of key cell signaling events required for initiation and progression of cancer might be best accomplished at the single cell level. The research, published by Cell Press in the October issue of the journal Cancer Cell, provides new insight that may lead to better diagnosis and treatment of some complex cancers.
Girls have harder time than boys adjusting in language-learning environment
Girls who don't share a common language may have more difficulty adjusting socially than boys, according to surprising new Michigan State University research looking at language acquisition among young children.
New Stanford diagnostic test for rare leukemia appears to give faster results, study finds
A new twist on a well-known cell sorting technique may allow physicians to diagnose rare leukemias in hours instead of weeks, according to a study by researchers at the Stanford University School of Medicine and UC-San Francisco. The clinical promise of the Stanford-developed approach, which eavesdrops on individual cells to decipher potentially dangerous molecular conversations, is likely to extend to many other disorders in which cell-signaling pathways are disrupted.
Seeing race and seeming racist? Whites go out of their way to avoid talking about race
White people – including children as young as 10 -- may avoid talking about race so as not to appear prejudiced, according to new research. But that approach often backfires as blacks tend to view this "colorblind" approach as evidence of prejudice, especially when race is clearly relevant.
Doctors: No hamsters or exotic pets for young kids
(AP) -- Warning: young children should not keep hedgehogs as pets - or hamsters, baby chicks, lizards and turtles, for that matter - because of risks for disease.
Jump seen in staph-linked flu deaths in kids
(AP) -- More children have died from flu because they also had staph infections, according to a new government report that urges parents to have their kids get the flu shot.
Corner stores capture kids on morning commute
In most cities, the corner store, with its chips, soda and candy, is ubiquitous. Convenient for the neighborhood residents, but also researchers are discovering, a major snack source for school age children.

Even minute levels of lead cause brain damage in children

Related stories:

News discussion: