[ RadSafe ] Re: DU and cancer causation

[Dan W McCarn]

Hello:

The following is a short quote from the Toxicological Profile for Uranium.
What are the values for airborne DU associated with combat situations?  Is
the exposure comparable to the values near the Jackpile Mine in New Mexico?
If exposure to natural uranium seems reasonably benign, what's the issue
about DU?

According to the following USDHHS publication, the health of uranium mill
workers did not reveal increased incidence of cancer, heart disease, or
kidney disease in spite of exposure to high airborne U (excluding
underground uranium miners with increased risk of lung cancer with > 120 WL
radon exposure / smoking).

Clearly this general statement is an over simplification ignoring particle
size and exposure route.

I would appreciate any more current / detailed references to the toxicology
of uranium from the group.

TOXICOLOGICAL PROFILE FOR URANIUM
U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES
Public Health Service
Agency for Toxic Substances and Disease Registry
September 1999

2. Health Effects, Page 19
"The National Research Council Committee on the Biological Effects of
Ionizing Radiation BEIR IV report stated that ingesting uranium in food and
water at the naturally occurring levels will not cause cancer or other
health problems in people. However, based on the zero-threshold linear
dose-response model (a conservative model that is inherently unverifiable
and is intended to be used as an aid to risk-benefit analysis and not for
predicting cancer deaths), the BEIR IV committee calculated that the
ingestion of an additional 1 pCi/day (0.0015 mg/day) of soluble natural
uranium would lead to a fractional increase in the incidence rate of
osteogenic sarcoma (bone cancer) of 0.0019. This means that over a period of
70 years (the nominal lifetime length), if everyone were exposed at that
level, the number of bone cancer cases in a U.S. population of 250 million
would increase from 183,750 to about 184,100."

Ibid, 2. Health Effects, Page 41
"Human and animal studies have shown that long-term retention in the lungs
of large quantities of inhaled insoluble uranium particles (e.g., carnotite
dust [4% uranium as uranium dioxide and triuranium octaoxide, 80–90% quartz,
and <10% feldspar]) can lead to serious respiratory effects. However,
animals exposed to high doses of purified uranium (as uranyl nitrate
hexahydrate, uranium tetrachloride, uranium dioxide, uranium trioxide,
uranium tetraoxide, uranium fluoride, or uranium acetate) through the
inhalation or oral route in acute-, intermediate-, or chronic-duration
exposures failed to develop these respiratory ailments. The lack of
significant pulmonary injury in animal studies with insoluble compounds
indicates that other factors, such as diverse inorganic particle abrasion or
chemical reactions, may contribute to these effects."

Ibid, 5.4.1 Air, Page 280
"Uranium in airborne dust appears to result from resuspension of soil and,
consequently, airborne dust has the same uranium concentration as the soil
particles that produce it. Airborne dust near uranium mining or milling
operations would be expected to contain higher than background levels of
total uranium and have an isotope ratio the same as crustal rock as long as
the surface material from which it originated had not experienced
significant weathering by moisture. Some examples of airborne uranium levels
near mining and milling operations when the industry was actively producing
uranium ore are included below for comparison with EPA values in Table 5-2.
The annual average concentration of uranium in ambient air taken near the
Jackpile Open Pit mine (New Mexico) was 2.4 fCi/m 3 (Eadie et al. 1979), and
the concentration of uranium in air measured near a Canadian refinery ranged
between 1.3 and 134 fCi/m 3 (2–200 ng/m 3 ) with a geometric mean of 13
fCi/m 3 (20 ng/m 3 ) (Tracy and Meyerhof 1987). Air samples taken near a
uranium mill tailings pile showed a uranium concentration of 1 pCi/m 3 (NCRP
1984a). Near the Paducah Gaseous Diffusion Plant in Kentucky, where uranium
enrichment is performed, the maximum total air alpha activity in 1979 at one
location was 0.7 pCi/m 3 (UCC 1980)."

Best regards,

Dan ii

Dan W. McCarn, AIPG CPG #10245, Wyoming PG #3031, EurGeol #462
504 East 23rd Street; Houston, TX 77008
Home: +1-832-767-0817; Cell: +1-505-710-3600

Institut für Geowissenschaften; Montanuniversität Leoben
Peter-Tunner-Strasse 5; A8700 Leoben, AUSTRIA
Cell: +43-676/725-6622; Fax; +43-3842-402-4902; Office: +43-3842-402-4903
mccarn at unileoben.ac.at


-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On Behalf
Of Jerry Cohen
Sent: Friday, August 11, 2006 16:17
To: Roger Helbig; radsafelist
Subject: [ RadSafe ] Re: DU and cancer causation

Debra Hastings relates a truly sad story suggesting that DU causes cancer. I
know of a gentleman who worked for 20 years in uranium processing during
which time he was exposed to DU on several occasions. He is now 85 years old
and in excellent health for someone his age. Doesn't that prove DU is
harmless??