[ RadSafe ] 1. CT Scans Can Cause Medical Device Malfunction FDA Advisory what is the mechanism

Fri Aug 8 07:20:17 CDT 2008

Not really sure what the motivation for the study was...but the FDA picked up on the article and ran with it.

McCollough et. al.Radiology: Volume 243: Number 3—June 2007

The basic gist is that you can have interaction between the electrons in the pacemaker with the incoming photons and cause a current flow.

Mike

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Today's Topics:

   1. CT Scans Can Cause Medical Device Malfunction FDA Advisory
      what is the mechanism (parthasarathy k s)
   2. RE: Fwd: [RADONPROFESSIONALS] Radon in granites
      (Brunette, Jeffrey J.)
   3. Low Dose Conference (Joel Cehn)
   4. Re: [Fwd: [riskanal] 10 Things to Scratch From Your Worry
      List]] (Alan Watts)
   5. RE: [Fwd: [riskanal] 10 Things to Scratch From YourWorry
      List]] (NIXON, Grant)
   6. RE: [Fwd: [riskanal] 10 Things to Scratch FromYourWorry
      List]] (Justin Harris)
   7. AW: [ RadSafe ] [Fwd: [riskanal] 10 Things to Scratch From
      YourWorry List]] (Rainer.Facius at dlr.de)
   8. Re: [Fwd: [riskanal] 10 Things to Scratch From Your Worry
      List]] (Maury Siskel)
   9. RE: [Fwd: [riskanal] 10 Things to Scratch FromYourWorry
      List]] (NIXON, Grant)
  10. Radon in granites  HPS letter to NYT (Wes Van Pelt)
  11. Re: Fallout exposure to the <5 mSv "control group" 2.7 to 10
      km from epicenter (Jim Muckerheide)
  12. RE: Nuclear mortality (Ross Beveridge)
  13. AW: [ RadSafe ] Nuclear mortality (Rainer.Facius at dlr.de)

----------------------------------------------------------------------

Message: 1
Date: Tue, 5 Aug 2008 10:08:07 +0000 (GMT)
From: parthasarathy k s 
Subject: [ RadSafe ] CT Scans Can Cause Medical Device Malfunction FDA
 Advisory what is the mechanism
To: radsafe 
Message-ID: <882036.93684.qm at web23104.mail.ird.yahoo.com>
Content-Type: text/plain; charset=utf-8

Friends,

Recently, US/FDA sent a warning that CT Scans Can Cause Medical Device to Malfunction The advisory states that one reason for the malfunction is the high radiation output of new C T equipment. Can any one explain the mechanism? 

Regards
K.S.Parthasarathy

      __________________________________________________________
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------------------------------

Message: 2
Date: Tue, 5 Aug 2008 10:06:41 -0500
From: "Brunette, Jeffrey J." 

Subject: RE: [ RadSafe ] Fwd: [RADONPROFESSIONALS] Radon in granites
To: 
Message-ID:
 <7BA43D870C5A5C41A44270C42379327A01BACB5D at MSGEBE20.mfad.mfroot.org>
Content-Type: text/plain; charset="UTF-8"

FYI - I see that the HPS has added a response to the "radon from granite countertop" think to their web site.  The link is http://hps.org/newsandevents/societynews.html#6581.  

I'll be honest, I've not been following the whole "radon in granite" issue, so this may have previously been discussed on RADSAFE.

Jeff Brunette

-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On Behalf Of Philip Egidi
Sent: Friday, August 01, 2008 11:26 AM
To: radsafe at radlab.nl
Subject: [ RadSafe ] Fwd: [RADONPROFESSIONALS] Radon in granites

This is from another listserv and may be of interest to some.
Phil Egidi

>>> Jim Otton  8/1/2008 8:56 AM >>>
Folks,

Here are two papers on radon in granites and related rocks. One
describes emanation in granites and the other the range of uranium
content in a small area of related but geochemically diverse plutonic
rocks in Massachusetts.   BTW many granites in southwestern Maine and
central New Hampshire are significantly radioactive due to high uranium
concentrations.

These annotated items are from Allan B. Tannerâ€™s US Geological Survey
Open File Report 92-351 â€œBibliography of radon in the outdoor
environment and selected references on gas mobility in the groundâ€
which is available online in three parts through the USGSâ€™ Publication
Warehouse at http://infotrek.er.usgs.gov/pubs/ 

Jim Otton

Uranium, radium and radon specialist 

U.S. Geological Survey

Hon, Rudolph, and Nancy M. Davis, 1989

Determinations of bulk emanation rates of selected granites by gamma
ray spectroscopy [abs.]:

Eos, Am. Geophys. Union Trans., 70(15): 496

Bulk radon (Rnâ€‘222) emanation rates of eleven selected granites,
predominantly from SE New England, were measured by gammaâ€‘ray
spectroscopy on a 16% efficiency REGE detector.  The employed technique
compares specific gamma emissions from isotopes that are precursors to
the radon stages with those that are subsequent to it.  Absolute
abundances are obtained through a calibration of absolute efficiencies
and by an instrumental neutron activation. Uranium abundances vary from
a low of 2 ppm to a high of 46 ppm.  Alkaline and peralkaline granites
show range between 5 and 10 ppm; whereas peraluminous and two- mica
granites give a typical range of 5 to 20 ppm with a few samples yielding
as high levels as 46 ppm.  Radon emanations appear to be only mildly
dependent on the absolute uranium concentrations but are strongly
dependent on the fragment sizes used in our experiments.  Emanation
rates for Rnâ€‘222 in bulk sized fragments (>4 inches average dimension)
yield rates as high as 20 to 25% (in alkali granites) but a more typical
range is less than 10%.  With decreasing fragment sizes to less than 100
Î¼m the emanation rates steadily increase up to 40 to 60% and possibly
even higher.  In contrast the maximum Rnâ€‘220 emanation rates for the
finest fraction are typically less than 10%.  We interpret these results
by a very different mode of distribution of uranium and thorium in these
rocks.  Thorium as a trace element is likely to be found on lattices of
resistant accessory minerals whereas uranium is most likely in form of
uranium minerals along microfractures.  These microfractures then
provide a mechanism for the higher Rnâ€‘222 release.

Loftenius, Christer J., and Rudolph Hon, 1989

Assessment of radon production levels in calc-alkalic plutons [abs.]:

Eos, Am. Geophys. Union Trans., 70(15): 496

Near-surface radon levels in areas associated with either peraluminous
or peralkalic granitic plutons have been well documented by a number of
the previous studies.  However, there is a lack of data for calc-alkalic
plutons which are the more common of the intrusive types.  Our study is
focussed on a calc-alkalic suite of rocks within the Sharpners Pond
Quartz Diorite Pluton of NE Massachusetts.  Geochemical study of 42
samples that includes every lithological type shows a presence of two
rock groups: (1) gabbroâ€‘diorites with average U: 1 ppm (range: <0.5 to
4.5 ppm), average Th: 4.6 ppm (0.4 to 9.6 ppm), and (2) granites with
average U: 5.2 ppm (2.9 to 8.2 ppm), average Th: 16.8 ppm (11.1 to 22.4
ppm).  Uranium abundances fail to correlate with most of the major or
trace elements, which suggests that a significant portion of U does not
appear to be part of the original rock mineralogy, but rather it is in
the form of secondary uranium-bearing minerals along open and healed
microfractures.  Our study of radon emanation rates on 10 selected
samples indicates that the bulk sample radon emanation is highly
variable (5-25%) supported by 0.5 to 1.5 ppm of the total U present in
the rock.  In summary: (1) the absolute levels of radon emanation from
the bulk samples of calcâ€‘alkalic intrusives are lower than those from
other types of granites; (2) levels of radon release into a pore space
in soils above such intrusions still pose a risk.  A significant part of
U does not appear to be "locked" in any of the weatheringâ€‘resistant
crystal structures (lack of correlation with Zr, rare-earth elements,
etc.) and consequently this U may become free and mobile during the
chemical weathering cycle.

---------------------------       RADONPROFESSIONALS -
http://list.uiowa.edu/archives/radonprofessionals.html    
---------------------------
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------------------------------

Message: 3
Date: Tue, 05 Aug 2008 12:33:30 -0400
From: Joel Cehn 
Subject: [ RadSafe ] Low Dose Conference
To: radsafe at radlab.nl
Message-ID: <8CAC53020D3CE34-1C10-3EEB at webmail-nb11.sysops.aol.com>
Content-Type: text/plain; charset="us-ascii"

Anyone going to the Lowrad 2008 conference on low dose effects?? The program has not been posted.? Anyone giving a paper?

http://www.lowrad2008.itn.pt/topics.html

Joel I. Cehn, CHP
Oakland, California
joelc at alum.wpi.edu 

------------------------------

Message: 4
Date: Tue, 05 Aug 2008 13:54:20 -0400
From: Alan Watts 
Subject: Re: [ RadSafe ] [Fwd: [riskanal] 10 Things to Scratch From
 Your Worry List]]
To: Maury Siskel , radsafe 
Message-ID: <5DBBCE0C1B3BE26F173DD89A at PC0848.facaux.ad.ohiou.edu>
Content-Type: text/plain; charset=us-ascii; format=flowed

 is this a hoax?

--On Monday, August 04, 2008 4:12 PM -0500 Maury Siskel 
 wrote:

> http://www.fumento.com/media/cellphone.html

------------------------------

Message: 5
Date: Tue, 5 Aug 2008 14:23:40 -0400
From: "NIXON, Grant" 
Subject: RE: [ RadSafe ] [Fwd: [riskanal] 10 Things to Scratch From
 YourWorry List]]
To: "Alan Watts" , "Maury Siskel"
 , "radsafe" 
Message-ID:
 <0C0642676B1D3B468D477A7D8DDFFEF660B834 at CATOM-MDMAPUWFE.mds.mdsinc.com>

Content-Type: text/plain; charset="us-ascii"

What a convenience! By the same token, I could be using my cellphone to
heat-up my lunch. This is great :)

Grant I. Nixon, Ph.D., P.Phys.
Science Specialist (Dosimetry/Physics/Engineering),
BEST Theratronics
413 March Road
Ottawa, ON  K2K 0E9
Canada
tel. (613) 591-2100 x2869
fax. (613) 591-2250

-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On
Behalf Of Alan Watts
Sent: Tuesday, August 05, 2008 1:54 PM
To: Maury Siskel; radsafe
Subject: Re: [ RadSafe ] [Fwd: [riskanal] 10 Things to Scratch From
YourWorry List]]

 is this a hoax?

--On Monday, August 04, 2008 4:12 PM -0500 Maury Siskel 
 wrote:

> http://www.fumento.com/media/cellphone.html

_______________________________________________
You are currently subscribed to the RadSafe mailing list

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------------------------------

Message: 6
Date: Tue, 5 Aug 2008 13:52:49 -0500
From: "Justin Harris" 
Subject: RE: [ RadSafe ] [Fwd: [riskanal] 10 Things to Scratch
 FromYourWorry List]]
To: "NIXON, Grant" , "Alan Watts"
 , "Maury Siskel" , "radsafe"

Message-ID:

Content-Type: text/plain; charset="us-ascii"

Done with a magnetron underneath the table.

Justin Harris
Radiation Safety Consultant
Suntrac Services, Inc.
Office:  281-338-2133
Cell:  281-728-2138
www.suntrac.com

-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On
Behalf Of NIXON, Grant
Sent: Tuesday, August 05, 2008 1:45 PM
To: Alan Watts; Maury Siskel; radsafe
Subject: RE: [ RadSafe ] [Fwd: [riskanal] 10 Things to Scratch
FromYourWorry List]]

What a convenience! By the same token, I could be using my cellphone to
heat-up my lunch. This is great :)

Grant I. Nixon, Ph.D., P.Phys.
Science Specialist (Dosimetry/Physics/Engineering),
BEST Theratronics
413 March Road
Ottawa, ON  K2K 0E9
Canada
tel. (613) 591-2100 x2869
fax. (613) 591-2250

-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On
Behalf Of Alan Watts
Sent: Tuesday, August 05, 2008 1:54 PM
To: Maury Siskel; radsafe
Subject: Re: [ RadSafe ] [Fwd: [riskanal] 10 Things to Scratch From
YourWorry List]]

 is this a hoax?

--On Monday, August 04, 2008 4:12 PM -0500 Maury Siskel 
 wrote:

> http://www.fumento.com/media/cellphone.html

_______________________________________________
You are currently subscribed to the RadSafe mailing list

Before posting a message to RadSafe be sure to have read and understood
the RadSafe rules. These can be found at:
http://radlab.nl/radsafe/radsaferules.html

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visit: http://radlab.nl/radsafe/
_______________________________________________
You are currently subscribed to the RadSafe mailing list

Before posting a message to RadSafe be sure to have read and understood
the RadSafe rules. These can be found at:
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For information on how to subscribe or unsubscribe and other settings
visit: http://radlab.nl/radsafe/

------------------------------

Message: 7
Date: Tue, 5 Aug 2008 20:49:31 +0200
From: 
Subject: AW: [ RadSafe ] [Fwd: [riskanal] 10 Things to Scratch From
 YourWorry List]]
To: , , 
Message-ID:
 <1B5EBED4E01074419C07EEF9D3802FDAF73E20 at exbe02.intra.dlr.de>
Content-Type: text/plain; charset="iso-8859-1"

". . . is this a hoax?"

Is this is a (serious) question ?

Regards, Rainer

________________________________

Von: radsafe-bounces at radlab.nl im Auftrag von Alan Watts
Gesendet: Di 05.08.2008 19:54
An: Maury Siskel; radsafe
Betreff: Re: [ RadSafe ] [Fwd: [riskanal] 10 Things to Scratch From YourWorry List]]

 is this a hoax?

--On Monday, August 04, 2008 4:12 PM -0500 Maury Siskel
 wrote:

> http://www.fumento.com/media/cellphone.html

_______________________________________________
You are currently subscribed to the RadSafe mailing list

Before posting a message to RadSafe be sure to have read and understood the RadSafe rules. These can be found at: http://radlab.nl/radsafe/radsaferules.html

For information on how to subscribe or unsubscribe and other settings visit: http://radlab.nl/radsafe/

------------------------------

Message: 8
Date: Tue, 05 Aug 2008 13:53:47 -0500
From: Maury Siskel 
Subject: Re: [ RadSafe ] [Fwd: [riskanal] 10 Things to Scratch From
 Your Worry List]]
To: Alan Watts 
Cc: radsafe 
Message-ID: <4898A1BB.2060004 at peoplepc.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Hi Alan,
 'fraid so but it is a pretty good looking stunt. Go snopes for more on 
the popcorn and a similar stunt with eggs.  Keep on talkin' -- we're OK
http://www.snopes.com/science/cookegg.asp

Cheers,
Maury&Dog
======================
Alan Watts wrote:

>  is this a hoax?
>
> --On Monday, August 04, 2008 4:12 PM -0500 Maury Siskel 
>  wrote:
>
>> http://www.fumento.com/media/cellphone.html
>
>
>
>
>
>

------------------------------

Message: 9
Date: Tue, 5 Aug 2008 15:12:19 -0400
From: "NIXON, Grant" 
Subject: RE: [ RadSafe ] [Fwd: [riskanal] 10 Things to Scratch
 FromYourWorry List]]
To: "Justin Harris" , "Alan Watts"
 , "Maury Siskel" , "radsafe"

Message-ID:
 <0C0642676B1D3B468D477A7D8DDFFEF660B86C at CATOM-MDMAPUWFE.mds.mdsinc.com>

Content-Type: text/plain; charset="us-ascii"

 - or, simply using a very "leaky" microwave oven, a heating element,
etc.

http://www.snopes.com/science/cookegg.asp

Grant

-----Original Message-----
From: Justin Harris [mailto:justin at suntrac.com] 
Sent: Tuesday, August 05, 2008 2:53 PM
To: NIXON, Grant; Alan Watts; Maury Siskel; radsafe
Subject: RE: [ RadSafe ] [Fwd: [riskanal] 10 Things to Scratch
FromYourWorry List]]

Done with a magnetron underneath the table.

Justin Harris
Radiation Safety Consultant
Suntrac Services, Inc.
Office:  281-338-2133
Cell:  281-728-2138
www.suntrac.com

-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On
Behalf Of NIXON, Grant
Sent: Tuesday, August 05, 2008 1:45 PM
To: Alan Watts; Maury Siskel; radsafe
Subject: RE: [ RadSafe ] [Fwd: [riskanal] 10 Things to Scratch
FromYourWorry List]]

What a convenience! By the same token, I could be using my cellphone to
heat-up my lunch. This is great :)

Grant I. Nixon, Ph.D., P.Phys.
Science Specialist (Dosimetry/Physics/Engineering),
BEST Theratronics
413 March Road
Ottawa, ON  K2K 0E9
Canada
tel. (613) 591-2100 x2869
fax. (613) 591-2250

-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On
Behalf Of Alan Watts
Sent: Tuesday, August 05, 2008 1:54 PM
To: Maury Siskel; radsafe
Subject: Re: [ RadSafe ] [Fwd: [riskanal] 10 Things to Scratch From
YourWorry List]]

 is this a hoax?

--On Monday, August 04, 2008 4:12 PM -0500 Maury Siskel 
 wrote:

> http://www.fumento.com/media/cellphone.html

_______________________________________________
You are currently subscribed to the RadSafe mailing list

Before posting a message to RadSafe be sure to have read and understood
the RadSafe rules. These can be found at:
http://radlab.nl/radsafe/radsaferules.html

For information on how to subscribe or unsubscribe and other settings
visit: http://radlab.nl/radsafe/
_______________________________________________
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For information on how to subscribe or unsubscribe and other settings
visit: http://radlab.nl/radsafe/

------------------------------

Message: 10
Date: Tue, 5 Aug 2008 17:28:20 -0400
From: "Wes Van Pelt" 
Subject: [ RadSafe ] Radon in granites  HPS letter to NYT
To: 
Cc: 'Wes Van Pelt' 
Message-ID: <001701c8f742$2f6fafd0$8e4f0f70$@net>
Content-Type: text/plain; charset="utf-8"

Radsafers,

I copied and paste below a paragraph from Dr. Toohey's letter to the NYT on radon in granite counter tops. (http://hps.org/documents/nyt_countertop_toohey-response.pdf )

    "Granite countertop external dose rate measurements that have been reported are about one and a half times greater than background dose rate measurements (or about 20 microroentgen/h). When one goes through the calculations, determining the amount of uranium in the countertop from this measurement and the amount of radon emanating from this), we find an average kitchen ambient radon concentration of 0.13 pCi/L, oneâ€eighth of the EPA recommended limit and oneâ€fourth of the natural ambient radon concentration in households across the United States."

Are these ratios correct!!?? I believe Dr. Toohey made an error in the math. I would have said: "... 0.13 pCi/L, 1/32 of the EPA recommended limit and oneâ€eighth of the natural ambient radon concentration in households..."

Can someone check my math? If we concur, we should notify the HPS ASAP.

=== message truncated ===

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