Re: [tlug] How much of radiations measured in Central Tokyo?

[Georgi Georgiev <chutz@example.com>]

Quoting Raymond Wan at 16/03/2011-21:01:42(+0900):
> Hi all,
> 
> I guess it is too late, but right now, there was a program on NHK
> called 緊急報告　福島原発 about the Fukushima problem.  It aired from 20:00 but
> since it is NHK :-), they will probably air it again.  The show was
> bilingual.
> 
> Among the many things they said is that the level of radiation
> yesterday morning:
> 
> Iwaki -- 23.72 micro-sievert
> Utsunomiya -- 1.318 micro-sievert
> Saitama -- 1.222 micro-sievert
> Shinjuku -- 0.809 micro-sievert
> Yokosuka -- 0.141 micro-sievert
> 
> traveling from the reactor to Yokosuka over an 8 hour period (4 am to
> 12 noon).  As a comparison [from the same show and not another
> source],
> 
> CT scan -- 6900 micro-sievert
> Tokyo --> New York flight -- 200 micro-sievert (I missed the part of
> whether or not it was a return flight)
> Chest X-ray -- 50 micro-sievert

I saw it, too, and was really annoyed at the confusion with the units.
Please correct me if my thinking is wrong, because I don't want to
be bashing NHK when I am at fault.

They said exactly what is quoted above and kept calling all units as
"microsieverts", even though the city measurements are *per hour*. The
ones they gave for comparison, though, are total exposures for the
duration of the event.

Let me clarify. They showed a bar with CT scan = 6900, flight = 200,
X-ray = 50. Then they put the Iwaki number on the graph and said "Look!
It's lower than the others".

Now let's try to convert from μSv to μSv/h, and vice versa.

On a Tokyo -> New York flight you receive 200μSv. The flight is 12h.
=> if you are in the plane heading to New York you are exposed to 200/12
= 16⅔μSv/h which is actually less than Iwaki's 23.72μSv/h.

Same goes for the X-ray. 2 days in Saitama = 1 X-ray. Are you
comfortable taking an X-ray every other day?

Just to clarify, I am not worried, but I believe they could have
presented the information more accurately.

-- 
(    Georgi Georgiev   (  The Lord prefers common-looking people.    (
 ) -------------------  ) That is the reason that He makes so many    )
(  ------------------- (  of them. -- Abraham Lincoln                (