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.