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Doubts remain about depleted uranium
By William Cole
Monday, May 14, 2007
http://the.honoluluadvertiser.com/article/2007/May/14/ln/FP705140355.html
The Army says its Stryker armored vehicles have
never fired depleted uranium rounds in Hawai'i, and
there is no intent for them to ever do so.
That leaves Dr. Lorrin Pang unsatisfied.
"I guess the community is a little bit worried about
(the Army's) credibility, so they would like to set
up for monitoring," said Pang, the state Health
Department's district officer for Maui County.
Pang, who also spent 24 years in the Army and was a
preventive medicine officer at Tripler Army Medical
Center in the late 1980s — and speaking as a private
citizen and not in his official capacity — supported
a bill that would have required regular soil testing
at Schofield Barracks for the presence of depleted
uranium.
The bill died in conference committee this past
legislative session.
The revelation in January 2006 that the Army had
found 15 tail assemblies from depleted uranium
aiming rounds used in a 1960s weapon, coupled with
the Stryker vehicle's ability to fire rounds with
the weakly radioactive material, is spreading new
concerns that the Army says are unfounded, and some
community members say amount to a potential health
risk.
Uranium is used primarily as fuel material in
nuclear power plants. Most reactors require enriched
uranium, which is extracted from naturally occurring
uranium. The uranium remaining after removal of the
enriched fraction is called depleted uranium, or DU,
which has about 60 percent of the radioactivity of
natural uranium.
DU is favored for armor-penetrating ordnance because
of its high density, which is approximately twice
that of lead. Depleted uranium is self-sharpening
upon impact and knifes through armor, while tungsten
penetrators tend to become blunt.
Increasingly, opponents of the Army's Stryker
brigade are linking the 19-ton vehicles and depleted
uranium ordnance.
A recent chairman's report from the Sierra Club's
Moku Loa Group on the Big Island states, "Strykers
fire weapons containing depleted uranium (DU), which
is radioactive and potentially health-threatening."
The group also said the "Army asserted that no DU
weapons were used at Schofield. Recently, this claim
has been proved wrong." The Army found the 15
depleted uranium tail assemblies and recently
confirmed to The Advertiser that it has found even
more fragments at the same Schofield firing range.
This summer, the Army will conduct radiological
testing at Schofield, Makua Military Reservation and
Pohakuloa Training Area on the Big Island for more
depleted uranium used in the 1960s with the Davy
Crockett, a recoilless rifle that could fire a
76-pound nuclear bomb.
Only dummy warheads were fired here, and the
depleted uranium came from smaller aiming rounds
that were used to simulate the trajectory of the
larger bomb. One Army veteran recalled firing inert
warheads at Schofield Barracks and the Pohakuloa
Training Area.
In e-mailed responses from the Pentagon, the Army
said although the Stryker Mobile Gun System, a
tanklike vehicle, can fire a 105 mm depleted uranium
round, it does not intend to use or stockpile such
munitions in Hawai'i. Stryker vehicles also can be
fitted to fire a 25 mm gun using depleted uranium
ammunition.
The Army said 27 of the expected 328 Stryker
vehicles on O'ahu will be Mobile Gun System
variants.
Army policy restricts the use of depleted uranium
during training to ranges licensed by the Nuclear
Regulatory Commission.
"The U.S. Army does not possess an NRC license to
fire DU in Hawai'i, nor do we intend to apply for an
NRC license for this purpose," the service said.
Although the steel armor of the M1A1 Abrams battle
tank is reinforced by a sandwiched layer of depleted
uranium, the Army said, "DU is not and will not be
used in the Stryker armor."
The Army said an NRC license may be required to
clean up ranges that were discovered to have the old
aiming rounds from the 1960s, which represented one
of the Army's first uses of depleted uranium.
"This determination will be made after the
historical research and initial range surveys are
completed this summer," it said.
Pang, Maui's district health officer, worries that
despite what the Army said, it may still be using
depleted uranium at Pohakuloa.
"Either that or they are stirring up a whole lot of
dust (with depleted uranium) that's there," he said.
Pang said the real danger with depleted uranium
comes with the vaporized or aerosolized form, which
occurs on impact.
"Once it's vaporized and breathed in, the alpha
particle emitters are the most dangerous form of
radiation of all, because it's up in close and it
sticks to the cells of your lung," he said.
The NRC regulates what it calls "source material,"
including depleted uranium, "to prevent misuse, to
provide for the common defense and security, and to
protect the health and safety of the public."
The World Health Organization said inhaled uranium
particles may lead to irradiation damage of the
lung. Measurements at sites where depleted uranium
munitions were used indicate only localized
contamination within a few yards of the impact site,
the organization said.
The Defense Department, meanwhile, maintains that
even when breathed or eaten, small amounts of
depleted uranium carry no expected radiological
health effects because the radioactivity is so low.
Doug Fox, who lives in South Kona, said he used a
Geiger counter to test on April 21 downwind from
Pohakuloa, 35 miles from the range, and got a
radiation reading of 93 counts per minute. A typical
radiation background reading is up to 20 counts per
minute, he said.
"So this is an elevated reading," he said. He added
that he believes Stryker training was being
conducted at Pohakuloa at the time. The
3,900-soldier brigade is training for a deployment
to Iraq this year and is finishing up rotations with
the vehicles to the Big Island.
Readings taken elsewhere on the island were not
elevated, Fox said.
But Russell Takata, program manager for the state
Health Department's Noise, Radiation and Indoor Air
Quality Branch, questioned Fox's use of a Geiger
counter.
"I looked it up, and I basically (told him) for
background type readings, you really need something
that's a little more definitive at the low
background levels (to gauge whether radiation levels
are high)," Takata said. He added that the rule of
thumb is that any readings three times normal
background are suspect.
Takata said Fox also could have picked up readings
for potassium 40, a naturally occurring radioactive
material.
But to make sure, Takata said, he'll send someone
from his office in the next week or two to take
readings outside Pohakuloa with a gamma spectrometer
and sodium iodide detector, "and it will tell me
specifically what kind of isotopes are being kicked
up."
He doesn't expect to find depleted uranium
radiation.
"This is not something that's an imminent danger,"
he said, "(but) we'll go check it out."
Fox acknowledges he's not a professional in the
field of radiation. "I'm just one citizen trying to
find the answers to this because I'm living downwind
from this thing," he said.
The fact that the Army plans Stryker anti-armor
live-fire training "is kind of scary because the
anti-armor projectile they use in Iraq is depleted
uranium," Fox said.
He said he also believes the Geiger counters he's
used are accurate.
"The real problem about this is you can talk about
technical gizmos and stuff," he said, "but if the
methodology is no good, it doesn't matter what
gadget you've got. The only methodology that's going
to work is continuous monitoring."
Reach William Cole at
wcole@honoluluadvertiser.com . |
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