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

[Kalin KOZHUHAROV <me.kalin@example.com>]

Hi Georgi (via TLUG)

On Thu, Mar 17, 2011 at 00:39, Georgi Georgiev <chutz@example.com> wrote:
> 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.
>
You are perfectly right, I was very annoyed as well and send them a
note by mail explaining more or less that. One problem is, in Japanese
people tend to omit the "/h" part like 速度60キロ機制 and so on.

This is what I send in Japanese [問い合わせ番号 1097348_1097353]
現在USTREAMでNHKを見ているのですが、
数回も放射線の測定値について微妙に間違っていると感じています。

まずは、単位が日本語で言いにくいせいですが、表示は適切にしないで解説していることが多い。「μSv/h」と「μSv」はどれぐらいかと言うと速度を表す「km/h」と長さを表す「km」と考えられます。なので、一回のX線の写真は確かにμSvであり、どこかで最大80μSv/hで測定した放射線を比べることがだめです。もし、80μSv/hで外に5時間いれば、400μSvの量、1ヶ月にいれば57600μSv（57.6mSv）になります。

さらに、測定値の「どこどこ、本日の最大値はXXμSv/hでした」を表示するより、一日かけての平均も定時する必要がある。そして、比較するときに、24時間×平均値と24時間×最大値をX線等と比較する必要がある。

以上、宜しくお願いいたします。
Kalin.
-------
May be not perfect Japanese, but they should get it.

Cheers,
Kalin.