[ RadSafe ] What's a sievert?

Larry Addis ajess at clemson.edu
Thu Mar 17 22:13:37 CDT 2011


Sorry Mahmoud, I know what a rem, rad, Roentgen, sievert and gray are and I
thought it so obvious I didn't have to explain my point. Dose and dose rate
are obviously not the same thing. 

The quote was " acceptable dose RATE (not Dose or total exposure) for
Japanese radiation workers to about 10 chest X-rays."  That makes no sense.
Dose RATE has nothing to do with exposure without the function of TIME, the
duration of the exposure. I'm sure everyone on the list knows the
fundamentals of health physics or they probably wouldn't be here.

And in this situation I'd think something like 25 rem (250 milli sievert) to
a max of 100 rem (1 sievert) might be considered acceptable exposure for
what these rad workers are attempting to do. 

If you have ever measured the dose rate of a spent fuel element through a
foot to three feet of water, it will give you a better appreciation of what
the air dose rates might be like over the empty or partially empty spent
fuel pool(s) might be like right now. I don't even see how the helicopter
pilots have been able to fly over and attempt the futile effort of dropping
water on the pools that have the roofs blown off.

And I think chest x-ray exposure would depend on machine technique/settings
- kvp, mA and exposure duration.

Again sorry for the confusion,

LA, RSO
Clemson University

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Haleem, Mahmoud S.
Sent: Thursday, March 17, 2011 9:48 AM
To: 'The International Radiation Protection (Health Physics) Mailing List'
Subject: Re: [ RadSafe ] What's a sievert?

One Sievert is equivalent to 20000 chest X-rays assumes each chest X-ray is
5 mrem.

Mahmoud Haleem    

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Larry Addis
Sent: Wednesday, March 16, 2011 8:06 PM
To: 'The International Radiation Protection (Health Physics) Mailing List'
Subject: Re: [ RadSafe ] What's a sievert?

I'm sorry. Maybe I'm just a little slow, but that makes absolutely NO sense
to me. Dose rate? 

LA

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of
sarah.stewart at boehringer-ingelheim.com
Sent: Wednesday, March 16, 2011 4:27 PM
To: radsafe at health.phys.iit.edu
Subject: Re: [ RadSafe ] What's a sievert?

The best explanation I have heard thus far from the media was from a radio
broadcast.  The expert (who I believe was a contributing editor to
Scientific
American) compared the acceptable dose rate for Japanese radiation workers
to
about 10 chest X-rays.  

  
Sincerely, 
Sarah Stewart 
Environmental Health & Safety 
Boehringer-Ingelheim Pharmaceuticals, Inc. 
Ridgefield, CT 06877 
(203) 791-6493 


-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Cmtimmpe at aol.com
Sent: Wednesday, March 16, 2011 2:06 PM
To: radsafe at health.phys.iit.edu
Subject: [ RadSafe ] What's a sievert?

With respect to Message 1 of March 16, the majority of the public has no  
idea what a 'sievert' is much less confusing micro and milli.  Few of the  
news items I have seen put the dosage information in context to 'normal  
background' or 'action levels' or health affecting levels along with the  
accompanying exposure times.  No wonder there is so much fear - the
explanations 
should be in simpler, layman language. As for the discussion  mentioned by 
Roger, where was that discussion?  
 
Christopher  M. Timm, PE
Vice President/Senior Project Manager
PECOS Management  Services, Inc.
505-323-8355 - phone
505-323-2028 - fax
505-238-8174 -  mobile  

 

Message: 1
Date: Wed, 16 Mar 2011 09:04:22 -0400
From:  <edmond0033 at comcast.net>
Subject: Re: [ RadSafe ] NHK Live
To: "'The  International Radiation Protection \(Health Physics\)
Mailing  List'"  <radsafe at health.phys.iit.edu>,
<GeigerCounterEnthusiasts at yahoogroups.com>
Message-ID:  <DC73985AD8FB45288D6EB4516FF91A14 at EdmondPC>
Content-Type: text/plain;  format=flowed; charset="iso-8859-1";
reply-type=original

Unfortunately the Public and news people mistake  milli and micro for 
thousand and million respectively.

Ed  Baratta

-----Original Message----- 
From: Roger Helbig
Sent:  Wednesday, March 16, 2011 7:41 AM
To: 'The International Radiation Protection  (Health Physics) Mailing List' 
;  
GeigerCounterEnthusiasts at yahoogroups.com
Subject: [ RadSafe ] NHK  Live

There was good explanation just on about difference between milli  and
microSieverts and showing comparable doses in addition to the  radiation
measurements at various distances from  Fukushima



Roger




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