ADHD Linked to So-Called "Safe" Lead LevelsDec 6, 2007 | Parker Waichman LLP
Lead levels once considered safe could be putting some children at risk for Attention Deficit Hyperactivity Disorder (ADHD) says a new study. The research, conducted by the University of Michigan, is sure to cause concerns among parents already made anxious by this year's record number of recalls for lead-tainted toys.
Lead exposure is especially dangerous for children under 6 because they are still growing, and their brains are developing. If lead is ingested, it can cause behavioral problems, learning disabilities, seizures and even death. The symptoms of lead poisoning often mimic other illnesses. They include irritability; loss of appetite; weight loss; sluggishness; abdominal pain; vomiting; constipation and pallor from anemia. There are often no signs that a child has been exposed to lead, and a blood test is the only way to determine if someone is suffering from lead poisoning.
The University of Michigan study looked at 150 Lansing-area children with and without ADHD. According to the study, all of the children tested positive for some lead in their blood, although none had levels higher than the 10 micrograms per deciliter level currently considered unsafe by the Centers for Disease Control. Children with ADHD had higher levels of lead in the blood than those without the disorder, according to the study. The average blood lead level of children with ADHD in the MSU study was less than 1.3 mcg/dl.
The research findings support a growing body of national evidence suggesting there is no safe level of lead in the blood, said Joel Nigg, professor of psychology at Michigan State and study director. While the "safe" level for lead in the blood was lowered from 25 mcg/dl to 10 mcg/ld in 1991, some scientists are now calling for the level to be dropped to 5 mcg/dl or even lower. The link between ADHD and blood lead levels will also increase calls tougher regulations on items that contain lead and other harmful elements that can get into the food supply or local environment of children - from cosmetics to cleaning supplies to electronic goods.
This latest study will surely increase the anxiety of parents already concerned that their children have been exposed to dangerously high levels of lead found in some toys. This year, millions of Chinese-made toys have been recalled due to lead paint. Toy giant Mattel has issued 3 separate toy recalls for lead hazards and other problems. In June, the RC2 Company recalled more than 1 million lead-tainted Thomas and Friends toy trains. Children's jewelry and character notebooks have also been recalled for the same reason. Just this week, a consumer group published survey that found that hundreds of toys available for sale in stores contained dangerously high levels of lead.
The results of the University of Michigan ADHD study will be published in the February issue of Biological Psychiatry.