>Even minimal lead exposure not safe for kids
The news about lead, a heavy metal that has been shown to cause mental impairment in small children, has been getting better and better for decades—until now.
Researchers from Cornell University studied blood lead levels on 172 children between ages six months and 5 years and tested the IQs of the kids at 3 and 5 years of age. The study results were published in the April 17, 2003, issue of the New England Journal of Medicine.
The study found that children suffered mental impairments even at lead levels that were within the government-defined "safe" zone of 10 mcg/dl or lower. Kids with a lead level of 10 had IQs that were, on average, seven points lower than kids with a lead level of one mcg/dl. The findings were the same in the 3-year-olds as they were in the 5-year-olds. Mental impairments this large surprised the researchers, because lead levels higher than 10 mcg/dl—the subject of all previous studies of lead poisoning—have actually been associated with considerably smaller decreases in IQ.
"It appears that many children are passing their lead test but failing to escape the adverse consequences of low-level lead exposure," says Richard Canfield, lead author of the article.
Kids' blood levels of lead have dropped 80 percent in the past 30 years, and the federal government has repeatedly lowered it definition of safe levels to its current limit of 10 mcg/dl. The Centers for Disease Control and Prevention estimate that about 2 percent of children between 1 and 5 years old have lead levels above 10 mcg/dl. But about 10 percent have lead levels above 5 mcg/dl.
To back pack or not to back pack … that is the question
As school starts up again, the debate continues to rage over the risk of back and neck injuries in children who carry their books in backpacks.
Several recent studies have found conflicting results. On the one hand, some studies suggest that backpacks slung over one shoulder and loaded down with heavy books contribute to back pain, especially in teenage girls. Others indicate that sedentary lifestyles and the increasing epidemic of teenage obesity are more important factors. The May 1, 2003, issue of the journal Spine features two such conflicting reports.
Among the important points made by the two articles: Middle school aged children in the two Spine studies carried a lot of weight in their backpacks—an average of 17 to 18 pounds, representing up to 15 percent of the average student's body weight.
Pain was reported more frequently by girls than by boys.
Large numbers of students in both studies complained of back pain.
In one study, almost three quarters of students complained of back pain. Those who carried heavier backpacks were more likely to be in pain.
In the other study, nearly half of students had back problems. However, pain level was not related to the weights of the backpacks but rather to other problems, such as headaches and fatigue.
For now, experts are recommending that parents and school kids use common sense. If your student is carrying a heavy load, encourage her to use both shoulder straps, and encourage her to leave as many books in her locker between classes as possible so that the heaviest load is saved for the trips to and from home.
Blood pressure control starts with infant formula
You already know the drill for your own healthy blood pressure: exercise, weight control, and a healthy diet low in salt and saturated fats. So what does all this have to do with baby formula?
Researchers from Europe studied 147 children who had been fed formula as infants. About half of the children were fed regular baby formula, while the other group were fed formula supplemented with a kind of fat found in a mother's breast milk but not in regular formula. The scientists then took blood pressure measurements of the children when they reached six years of age. Their results were published in the May 3, 2003, issue of British Medical Journal.
They found that children fed the special formula had blood pressures that were lower than those of children fed traditional formula. In fact, the blood pressures of the special formula-fed children were about the same as children who had been breast-fed as infants.
The results are important because precursors of high blood pressure often begin in childhood, and children with lower blood pressures are less likely to develop high blood pressure as adults.
Bed sharing and soft mattresses increase risk for SIDS
Scientists have known for a long time that putting baby to bed on his back helps reduce the risk of Sudden Infant Death Syndrome, or SIDS, a mysterious condition in which infants under 1 year of age stop breathing and die in their sleep. Now there are new risk factors to add to the list.
Researchers reviewed the charts of 260 Chicago area infants who died of SIDS between 1993 and 1996 to discover any trends among them. The scientists also studied living infants for comparison. Their findings were published in the May, 2003, issue of Pediatrics.
As expected, researchers found that SIDS babies were 2.4 times more likely to have been put to sleep on their stomachs compared with babies who survived the first year. They also found that the infants who died of SIDS were 5.4 times more likely to have shared a bed with other children than were the healthy infants. Sharing a bed with parents did not prove to be an important risk. Scientists also discovered that babies who had died of SIDS were five times more likely to have slept on a soft mattress than the living babies.
Surprisingly, infants who slept both on their stomachs and on a soft mattress had 21 times the risk of SIDS as kids who slept both on their backs and on a firm mattress, much more than expected.
Parents "should receive instruction that emphasizes supine sleeping, firm bedding, not using pillows and not sharing a bed with other children or sleeping with another person on a sofa," the authors wrote.
Kids who watch smoking in movies may pick up the habit
You already know that kids whose parents or close friends smoke are more likely to smoke themselves. But new evidence suggests that even Hollywood can have a profound impact on the urge to light up.
Researchers from England and Dartmouth Medical School in New Hampshire watched pieces of 50 popular contemporary movies to identify the number of times someone in the movie smoked a cigarette. They then interviewed 3,500 non-smokers aged 10 to 14 years at the beginning and the end of the study, one to two years later. Their results were published in the June 10, 2003, issue of The Lancet.
They found that 10 percent of the kids had tried smoking in between the two interviews. But the teenagers who had viewed the most smoking in movies were more than three times as likely to have started smoking themselves than were the teenagers who had seen the least smoking in movies.
"Our results provide strong evidence that viewing smoking in movies promotes smoking initiation among adolescents," says Madeline Daulton, a lead researcher.
Fascinating kid facts
• Head lice are not as easy to catch as once thought. According to research in the June 7, 2003, issue of British Medical Journal, over-the-counter treatments are very effective, banning infested children from school is unnecessary, and lice shed onto clothing or furniture do not live long enough to infect anyone new.
• Help keep your little ones from getting influenza this winter. The American Academy of Pediatrics, the Centers for Disease Control and Prevention, and the American Academy of Family Physicians recommend flu shots for all children between 6 and 24 months of age. Flu shots generally become available in October each year.
The National Institute of Child Health and Human Development (NICHD) is looking for pregnant women who are carrying babies with spina bifida, a condition in which the spinal bones don't fuse properly, allowing the spinal cord to bulge out of the back. NICHD plans to conduct a study comparing traditional surgery to surgery done while the baby is still in the womb before birth. For more information, call the NICHD at 1-866-ASK-MOMS or see the NICHD website: www.spinabifidamoms.com.
Dale Mazer is an internal medicine specialist who also has a degree in public health.