Study links lead with ADHD in children



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Posted on April 10, 2010 at 12:34 PM

Updated Saturday, Apr 10 at 4:45 PM

You would never suspect 2-year-old Bella was put in danger by an old environmental toxin, lead. But last year her mother had a nagging feeling.

"It was just a hunch. And it was such an unlikely hunch that I figured I should act on it," said Katrine Jensen.

Public health experts say there's an entrenched belief that lead is not a problem in our state. And Bella's pediatrician wasn't worried.

"She said if I was concerned we should test, although she didn't think she was at risk, because this is not old paint," said Katrine.

But a simple blood test revealed the lead in Bella's body was well above what the federal government considers normal.

It's a test Dr. Catherine Karr thinks more children should get. She heads the pediatric environmental specialty unit at the University of Washington.

"We haven't had a long legacy or history of frank poisoning with lead in our area, it's not so much on the radar screen for the usual, the average pediatrician," said Dr. Karr.

She says more and more research shows even low lead levels can harm children.

The latest study showed a link between lead in children and parent and teacher reports of ADHD symptoms like hyperactivity and attention problems.

So how much lead is too much?

"There is no safe level of lead exposure. We don't have a threshold below which we don't see effects especially on IQ cognitive ability in children," said Dr. Karr.

Some toys contain lead, so Bella's parents replaced hers. The health department tested the home, including the old paint. Lead in paint wasn't banned until 1978.

They took samples of the drinking water. Old pipes can leach lead. Those and soil are the main suspects for lead exposure.

An estate sale trunk with old lead paint was the culprit. Bella had used it to pull up when she started to walk.

"I think it was her just sucking on the corners that did it," said Katrine.

Bella still has detectable lead in her blood more than a year after her exposure.

More information

Center for Disease Control information

Seattle King County Public Health