AW: [ RadSafe ] Article: Nevada wells test positive for polonium

Thu Nov 8 16:01:36 CST 2007

RADSAFErs,

This article is interesting, but I miss any real information about
concentrations found or comparisons with legal limits. "high concentrations"
- how high? "gross alpha radioactivity" - what is the meaning of this
comparison? I have been fighting this gross alpha radioactivity (and as well
the gross beta and the gross alpha-beta radioactivity) since decades). It
still has not died out. What about Pb-210?

A typical bla-bla article - a few correct facts are mixed with hearsay,
maybe (leukemia) information, a little horror (Litvinenko!!!), bla-bla-bla.
There is enough literature available about Po-210 (and Pb-210) in well water
in Scandinavia. I know of no such alarmist messages from Scandinavia. 

I sent this message on Thursday, Nov. 8, 2007 at about 22:55 Middle European
Wintertime. From previous experience I would expect it to be distributed
after a few days, which sure is not the goal of a discussion forum. 

Best regards,

Franz

Franz Schoenhofer, PhD
MinRat i.R.
Habicherg. 31/7
A-1160 Wien/Vienna
AUSTRIA

-----Ursprüngliche Nachricht-----
Von: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] Im Auftrag
von John Jacobus
Gesendet: Donnerstag, 08. November 2007 15:30
An: radsafe; know_nukes at yahoogroups.com
Betreff: [ RadSafe ] Article: Nevada wells test positive for polonium

>From GEOTIMES, November 2007 at
http://www.geotimes.org/nov07/article.html?id=nn_polonium.html

Science and Society
Nevada wells test positive for polonium

Courtesy of Ralph Seiler 
U.S. Geological Survey hydrologist Jena Green tests
the water at a municipal well in Churchill County,
Nev., an area where researchers have found high
polonium-210 concentrations in the groundwater. 
On Aug. 3, 2007, the U.S. Geological Survey (USGS)
reported to well owners that 25 wells in Lahontan
Valley in Churchill County, Nev., contained the
carcinogenic, radioactive isotope polonium-210. Of
these wells, 13 exceeded the U.S. Environmental
Protection Agency’s (EPA) Maximum Contaminant Level
for “gross alpha radioactivity” in a public water
supply. The average polonium-210 concentrations in the
wells exceeded typical groundwater concentrations.
Just how that polonium got into the water is
debatable. 

USGS researchers say that there is no evidence that
the polonium-210 came from human activity, such as the
nuclear testing that occurred in Nevada during the
20th century. Instead, they think that the
polonium-210 in the well water is a natural product of
the radioactive decay of uranium in the aquifer
matrix. Researchers suspect that the uranium, which
does not occur naturally in the rocks in Churchill
County, was likely carried into the valley by streams
that eroded uranium-bearing granites in the Sierra
Nevada during the Pleistocene about 1.8 million to
11,000 years ago, according to Ralph Seiler, a USGS
hydrologist in Reno, Nev., who led the study of the
well water. That uranium now sits in the aquifer,
decaying into polonium-210 before entering the water
supply. The mystery, Seiler says, is why polonium-210
is so high in Churchill County in particular, when
granitic rocks and uranium are generally prevalent
across the region. 

The new analysis by Seiler and colleagues follows up
on a 2001 study, in which USGS researchers sampled 100
Churchill County wells as part of an investigation of
a cancer cluster. Between 1997 and 2002, 16 children
in Churchill County were diagnosed with acute
leukemia. Out of a total county population of about
24,000, this is an anomalous incidence rate, 20 times
the national average. The cause of the sudden outbreak
remains unknown, but hypotheses range from the high
polonium concentrations in the water to genetic
variation in the patients to environmental toxins
caused by jet fuel spills, pesticides and a local
tungsten refinery. Researchers are currently
investigating both environmental and genetic factors
that might have contributed to the leukemia cluster.

Chris Pritsos, a biochemist at the University of
Nevada at Reno, is studying the physiological effects
of ingesting the well water in Churchill County. At
this point in time, he says that he does not know
whether the water contributed to the leukemia cluster
that began in the late 1990s. Pritsos is looking at
oxidative stress and immune function in mice whose
drinking water comes from the Churchill County wells,
and notes that in addition to polonium-210, the water
is also high in arsenic and tungsten, which can both
be toxic. He also says that the connection between
ingested polonium-210 and leukemia may be less
pronounced than, for example, the connection between
lung cancer and polonium-210 inhaled from cigarette
smoke, because the inhaled radiation is deposited
directly to the lung tissue, whereas radiation
ingested from drinking water passes through the liver
and spleen before it reaches the bone marrow. 

The current study found the median concentration of
polonium-210 in the 25 wells in Churchill County to be
18 picocuries per liter, with a maximum of 67.7
picocuries per liter and a minimum of less than 0.1
picocuries per liter, making the median polonium-210
concentration in a liter of the well water roughly
five to six times greater than the amount in a pack of
cigarettes, but hundreds of millions of times less
than the amount that poisoned and killed Russian spy
Alexander Litvinenko in November 2006. Though EPA has
not set a drinking water standard specifically for
polonium, the level of polonium-210 in most of the
sampled wells pushed them over EPA’s Maximum
Contaminant Level for gross alpha radioactivity, which
is 15 picocuries per liter. Of the 25 wells tested in
Churchill County, researchers only found high
polonium-210 concentrations in private wells, Seiler
says. The city of Fallon and Churchill County sampled
their own municipal wells and found them to be safe.

Finding concentrations of polonium-210 greater than 10
picocuries per liter is rare, Seiler says, and has
occurred only in a few wells in the United States,
including 30 to 40 wells east of Tampa, Fla., a single
well in Alexandria, La., a well in an undisclosed
location in California and the Churchill County wells.
What all the wells have in common, Seiler says, is
contact with uranium sources and, in the Florida and
Nevada wells, waters with low oxygen levels. The
Florida wells are characterized by dilute acidic
waters, while the Nevada wells are more saline and
alkaline. These areas also appear to have
sulfate-reducing bacteria. But the story doesn’t end
there, he says. “We need to do more research” to
further identify what the areas have in common, he
adds, “so we can predict where polonium-210 will be a
problem.”

Jenna Beck
Geotimes contributing writer

+++++++++++++++++++
"If you guard your toothbrushes and diamonds with equal zeal, you'll
probably lose fewer toothbrushes and more diamonds."
- Former national security advised McGeorge Bundy
-- John
John Jacobus, MS
Certified Health Physicist
e-mail:  crispy_bird at yahoo.com

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