Women exposed to lead in childhood may pass poison to their kids.

A girl poisoned by lead in her childhood may, years later, pass the toxin on to her children during pregnancy, scientists say.

Researchers have known for years that children exposed to lead, usually by ingesting peeling paint or inhaling lead-tainted dust in aging or dilapidated homes, store large amounts of it in their bones. The exposure to lead can cause severe developmental delays and sometimes retardation.

A preliminary research report released in June, however, shows that the stored lead "leaches" from bones during the second and third trimesters of a lead-exposed woman's pregnancy, said William Jameson, a scientist at the National Institute of Environmental Health Sciences (NIEHS), which funded the study.

"During pregnancy, the fetus gets the calcium it needs by making a big draw on the mother's bone stores," Jameson explained. "This large demand on the mother's bones creates an avenue for the lead to be released. Whether this actually affects the child's development has yet to be studied."

Jameson added, though, that "one could assume" this leaching action would harm a developing fetus.

"The other thing that might happen is that as a woman grows older, she may develop osteoporosis, which also may trigger a release of lead from the bones. What affect that may have, I don't know."

Jameson said that pregnant women may take supplements to place calcium in the bloodstream for the fetus, thus reducing the amount of calcium--and lead--the child takes from the mother's bones.

Lead poisoning is the number one environmental health hazard for infants and toddlers, according to the EPA. One in 11 have blood-lead levels of more than 10 micrograms per deciliter, the point at which the agency says that injury may result.

NIEHS researchers currently are studying whether succimer, a drug known to reduce blood-lead levels in male workers exposed to large amounts of lead, can help children exposed to small amounts.

"Succimer is only approved for children whose blood lead-levels exceed 45 micrograms per deciliter," according to NIEHS documents. "However, children with blood-lead levels well below this figure have cognitive impairment. It is not known whether reductions in blood lead at these levels will prevent the effects of lead on cognitive function."

In an unrelated action, the U.S. Consumer Product Safety Commission in June warned that some imported vinyl miniblinds may pose a lead-poisoning hazard for young children. The commission said lead is added to stabilize the plastic in these blinds. Sunlight and heat can break down the plastic and form lead dust on the surfaces of the slats. Blinds made in the United States in the past 20 years have not contained lead, the commission said.

For more information on the preliminary report, contact NIEHS at P.O. Box 12233, Research Triangle Park, NC 27709-2233.