Officials Blast EPA on Perchlorate Standards
Federal and state experts say the new goal for the toxic contaminant
will put children at risk.
By Marla Cone, Times Staff Writer
March 16, 2006

Warning that babies are especially vulnerable, a federal panel of
scientists has lambasted the Environmental Protection Agency's health
goal for a toxic chemical that has widely contaminated drinking water
and foods, particularly in Southern California.

The EPA's new goal for perchlorate, an ingredient of solid rocket
fuel, "is not supported by the underlying science and can result in
exposures that pose neurodevelopmental risks in early life," wrote
Melanie Marty of California's Office of Environmental Health Hazard
Assessment, who chairs the EPA's Children's Health Protection Advisory
Committee.

The letter from the committee of 26 scientists, sent to EPA
Administrator Stephen L. Johnson on March 8, warned the agency that it
is putting babies at unnecessary risk of neurological damage. The
EPA's interim goal for perchlorate, announced in January, "does not
protect infants and should be lowered," the scientists said in their
letter.

It is the second time in less than two months that an EPA scientific
advisory panel has criticized the Bush administration for proposing a
standard or guideline for a pollutant that would not adequately
protect public health.

Most perchlorate contamination comes from military bases and aerospace
plants. In California, at least 350 water wells have been contaminated
by perchlorate, largely in the Los Angeles Basin, according to the
Department of Health Services, and it has also tainted supplies in
about 40 other states.

There is no current enforceable national standard for perchlorate in
drinking water. But six weeks ago, the EPA set an interim goal of 24.5
parts per billion. The idea was to guide cleanup of industrial and
Pentagon waste sites and contaminated drinking water until the federal
agency decides on a standard that drinking water must meet.

California recently proposed a much tighter goal of 6 ppb, and on
Monday, Massachusetts proposed a standard of 2 ppb. California's goal,
set by Marty's agency, is not enforceable because the state Department
of Health Services has not yet set a drinking water standard.

In animal studies, perchlorate has been shown to disrupt thyroid
hormones. Low thyroid hormone levels can obstruct the brain
development of fetuses and young children, causing subtle reductions
in their intelligence and other mental abilities.

EPA officials were unavailable Wednesday for comment on the letter.

The EPA has said its decision was based on a 2005 recommendation of a
"safe" dose from a committee from the National Academy of Sciences.

Some scientists have questioned the findings of that committee, saying
that the dose was set too high, and also suggested that the EPA is
misconstruing some of its advice.

The scientists on the children's health panel said they were troubled
that the EPA's goal assumes that exposure comes only from drinking
water, not from food. Perchlorate has been widely found in milk,
cheese, lettuce and other crops, which are tainted by irrigation
water, as well as in human breast milk and baby formula.

Out of 33 samples of milk purchased in Los Angeles and Orange counties
in 2004, perchlorate was found in all but one, according to tests by
the Environmental Working Group, an environmental health advocacy group.

The scientists on the committee wrote that food tainted by
perchlorate-contaminated irrigation water "is an obvious concern given
the widespread detection of perchlorate in lettuce and milk."

They advised the EPA to set an enforceable standard for drinking
water, and to pay special attention to protecting fetuses from
perchlorate exposure in the womb and babies from contamination from
breast milk or formula.

"Perchlorate is an important … toxicant because of widespread exposure
and the potential for impairment of the thyroid during critical stages
of brain development," Marty wrote. "The risk posed by this
environmental agent is preventable by appropriate agency action."

"It's time for the EPA to wake up and listen to what the states and
its own advisors are saying: Perchlorate is a threat to children at
very small doses," said Renee Sharp, an Environmental Working Group
scientist who obtained the scientists' letter Tuesday. "The Bush
administration has given no sign that it's going to set a national
drinking water standard, and the EPA's recommendations leave children
at risk."

The Environmental Working Group, which has advocated a perchlorate
standard of 1 ppb or 2 ppb, , said that an average 1-year-old,
weighing about 25 pounds, would exceed the EPA's safe dose for
perchlorate after drinking just one cup of milk per day.

Perchlorate is widely used by the U.S. military and defense
contractors as the explosive component of rocket propellants, and also
is used in fireworks and other explosives. It has been found at 45 of
the nation's 1,500 Superfund sites, which are the nation's worst
hazardous waste sites, and the EPA's goal would affect the extent of
cleanup there and at other sites.

Sources of the contaminant include the now-closed Kerr-McGee chemical
plant near Las Vegas, which contaminated the Colorado River, which
provides drinking and irrigation water in Southern California.

That contamination has been reduced by a company-sponsored cleanup.

In February, the EPA's clean-air scientific review committee
challenged the agency's proposed health standards governing
particulates, tiny pieces of soot that are considered the nation's
deadliest air pollutant.

The scientists said the agency ignored most of their recommendations
to curb particulates, which could lead to additional heart attacks and
deaths from asthma and other respiratory ailments.