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Public health chief discounts need
because guilty pipes are being replaced.
by Julie Davidow, Seattle Post-Intelligencer, July 7, 2004
Children who sipped water from lead-contaminated fountains at
Seattle's public schools probably didn't drink enough for their blood
to register levels of the heavy metal considered hazardous by federal
standards.
Still, health experts said, it's an unacceptable level of risk.
"Those are extremely high levels of lead that children are being
exposed to, and it shouldn't be happening," said Dr. Bruce Lanphear,
professor of children's environmental health at Children's Hospital
Medical Center in Cincinnati. [Note: Lanphear's name was misspelled in
the original version of this article]
Recent studies indicate a child's IQ can drop several points even at
blood lead levels below 10 micrograms per deciliter, the established
elevated blood lead level for children.
"For any one child, it's not that big of a deal," said Lanphear,
author of a 2001 study that found a decline in IQ in children with
blood lead levels below 10 micrograms. "But on a population level,
it's quite troubling."
At higher levels, lead poisoning is known to cause reading and
learning disabilities, impaired hearing, reduced attention span,
hyperactivity and irritability.
Alonzo Plough, director of Public Health -- Seattle & King County,
said the county isn't offering any special lead testing in response to
the unsafe drinking water at Seattle schools.
There's no need, because the district is responding by replacing the
guilty pipes, Plough said.
"The nature and duration of these exposures is highly unlikely to
create any lead poisoning of a clinical nature," Plough said.
Lead levels typically peak in children around age 2, said Lanphear,
while they're still crawling and putting everything they find in their
mouths.
In old homes and neighborhoods, toddlers ingest lead through dust and
paint chips -- which carry more concentrated amounts of the heavy
metal than drinking water.
For example, a drinking fountain at Seattle's Alternative Elementary
No. 2 contained water flowing with lead measured at 1,600 parts per
billion -- 80 times greater than the Environmental Protection Agency's
limit of 20 parts per billion.
But a lead paint chip can contain lead levels up to 160,000 parts per
million, Lanphear said.
"Probably water by itself will not lead to extremely high blood lead
levels in children," said Lanphear.
In the body, lead first enters the bloodstream, migrates to soft
tissue, such as the brain and kidneys, and eventually settles in bone.
Detectable levels of lead linger in the blood for about 30 days,
according to Jude Van Buren, who oversees the children's blood lead
registry for the Washington Health Department.
If a parent suspects their child has been exposed to high levels of
lead, a simple blood test -- either taken from a finger prick or drawn
from the vein -- can determine their blood lead level.
Recent studies suggest lead accumulations in bone may be more to blame
for the deleterious affects of lead exposure than blood levels,
according to the Office of Children's Health Protection at the EPA.
Pregnant women are also considered particularly vulnerable to lead
exposure.
A study in Mexico City found a higher rate of miscarriage connected to
blood lead levels between 5 and 9 micrograms per deciliter in pregnant
women, according to Lanphear.
Most pediatricians will do the blood test, which costs about $25 to
$40.
Laboratories are required to report the results of all blood lead
tests to the state, but there's no requirement to screen children for
lead, Van Buren said.
Between 2002 and 2003, 12,454 children -- from newborns to age 6 --
were tested in Washington state. Of those, 158 had blood lead levels
at 10 micrograms per deciliter or above.
Since the early 1980s, after lead was removed from gasoline, the
average blood lead level in children under 5 dropped from 16.5
micrograms per deciliter to 3.6 micrograms in the early 1990s.
Some evidence suggests calcium and iron could help shield children
from lead exposure by blocking access to bone and soft tissue, but
there's no medically proven treatment for lead poisoning, Lanphear
said.
If an elevated blood lead level is detected, parents can work with
their pediatrician to find and weed out all potential sources of lead,
experts say.
"You can't assume that lead came from one source," Van Buren said.
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