AW: Bq soon

["Franz Schoenhofer" <franz.schoenhofer@chello.at>]

-----Ursprüngliche Nachricht-----

Von: owner-radsafe@list.vanderbilt.edu

[mailto:owner-radsafe@list.vanderbilt.edu]Im Auftrag von Neil, David M

Gesendet: Dienstag, 08. April 2003 16:52

An: Graham Roger Stevenson; William V Lipton

Cc: Faillace, Ernie; Michael G. Stabin; radsafe@list.vanderbilt.edu

Betreff: RE: Bq soon



Perception changes rather fast - may I refer you to the change of perceived

danger from the Chernobyl accident and the follow up, which was by no means

a question of microCuries/kg or of microSv/what so ever.



Best regards,



Franz































I think part of the acceptance problem may be in perception.  As Sandy

mentioned, a Curie is "oversized" (most measurements end up as milli- or

micro-), but a Becquerel is "undersized" (notwithstanding it IS a natural

unitary measure).  This means that reported quantities are typically in

megaBequerels - and J.Q. Public does understand that mega- means "a lot of",

whether or not the precise multiplier is understood.  This means that a

quantity that was reported as microCuries (micro- ? no big deal) is now

reported as megaBequerels (mega- ? we're all gonna die! :-P).



The comment below on Grays and Sieverts reflects this also. The qualitative

change between Rads/Roentgens and Grays/Sieverts is less than for Curies and

Becquerels.



Similar logic seems to apply to other unit conversions - a liter is a

reasonable quantity to drink, a meter of cloth is a reasonable amount to

hold up.  This may also apply to the inertia in adopting Centigrade/Celsius

in everyday measure - in Fahrenheit, 100 is darn hot weather, and 0 is real

cold; whereas in Celsius, 0 is just chilly, and hot weather is around 37.

100 is not directly perceivable, just a physical constant.  (As a side note,

100 Fahrenheit was supposed to be human core body temperature - seems he was

running a mild fever the day he calibrated his new instrument ;-D )



So, while I disagree that "Perception is reality", the old saw that "Man is

the measure of all things" has some application in perception.



Dave Neil



-----Original Message-----

From: Graham Roger Stevenson [mailto:Graham.Stevenson@cern.ch]

Sent: Tuesday, April 08, 2003 2:43 AM

To: William V Lipton

Cc: Faillace, Ernie; Michael G. Stabin; radsafe@list.vanderbilt.edu

Subject: Re: Bq soon





Greetings!



A few comments on SI units may help to calm personal fears - it is not at

all as bad as you think it might be!



<SNIP>

Becquerels for ever! but I still have some regrets about the passing of the

millirem.  The innate danger levels are still there though in the new

system.

Sieverts and Grays are lethal, millisieverts are nasty, microsieverts don't

count unless there are lots of them and who cares about nanosieverts!



Graham

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| Graham R. Stevenson,         | Email: Graham.Stevenson@cern.ch |

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