Doctor urges testing for lead in learning-disabled children

Scott Sonner

Thursday, Feb. 17, 2000 | 8:51 a.m.

RENO, Nev. - A leading pediatrician who is urging more research on the harm toxic chemicals cause children says every child with a learning disability should be tested for lead poisoning.

"We simply do not know the causes of more than 80 percent of learning disabilities in children," said Dr. Philip Landrigan, director of the Children's Center for Health and the Environment at New York City's Mount Sinai School of Medicine.

"We need - more than we have in the past - to consider the possibility that some fraction of those disabilities are caused by toxic chemicals in the environment," he said.

He said he will propose the blood-testing in his keynote address today at the 37th Annual Conference of the Learning Disabilities Association of America in Reno.

A former adviser on children's health at the Environmental Protection Agency, Landrigan directed the U.S. national program in occupational epidemiology from 1979 to 1985 as the head of hazard evaluations and field studies at the National Institute of Occupational Safety and Health in Cincinnati.

"We already know that certain toxic chemicals can cause learning disabilities in children and other things like dyslexia and autism," Landrigan said.

Along with lead, PCBs, a man-made chemical compound, and pesticides are among the most common, he said.

"I'm going to make the argument that research needs to be looking at more chemicals to see what toxic effects they may have on children's developing brains," he said.

The four-day conference examines learning disabilities from prenatal and early childhood to school age and adult years.

More than 200 scheduled sessions include presentations by researchers from Johns Hopkins University School of Medicine, Yale University School of Medicine, University of Rochester Medical School and the National Institutes of Health.

Most of the professionals attending are involved in caring for children with learning disabilities, Landrigan said.

"The focus has been on finding the best ways to treat children who have the problems," he said.

"Now we are hoping to engage these good people in a new endeavor: the causes."

Doctors, teachers and daycare workers need to pay more attention to the possibility toxins play a role in a child's individual disability, said Landrigan, a former member of the Presidential Advisory Committee on Gulf War Veteran's Illnesses.

Pediatricians should always ask the parents of a child with a learning disability what toxic exposures they may have suffered at work, he said.

"Lead is best understood poison for children's brains, partly because so many children have suffered from it," Landrigan said.

"The removal of lead from gasoline has brought about some enormous reductions, he said.

Nevertheless, an estimated 940,000 American children have elevated levels in their blood, he said.

PCBs historically have been widely used in electrical transformers and generators. "And here in the Eastern United States, a lot of PCBs get dumped in rivers," Landrigan said in a telephone interview from New York.

"They are found in high concentrations of fish and shellfish. If a pregnant mom eats a lot of fish or shellfish, she can contaminate her baby.

"We're increasingly worried about the potential for certain pesticides to cause brain injury in children and that research is only getting under way," he said.

Some of the most commonly used pesticides are engineered to be toxic to nervous systems, from those dropped on crops from airplanes to those used in a garden or sprayed around a home's baseboards to control cockroaches, he said.