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Question about radioactive fallout

by F Gump
Tags: fallout, radioactive
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F Gump
#1
Apr7-05, 10:46 AM
P: 6
My uncle was in WWII, and after we bombed japan , he was send over there for some duty. When he came home he brought some belongings from japan, like his uniform, Gun,, ETC...He passed away this year and left some of his WWII things to me that he brought back from japan. My question is, IF these things were in japan after we droped the bomb, would they have residual radioactive dust still on them, in other words arent WWII collectibles from japan radilogicly contaminated? Thank you for any help, as i dont know much about how fall out all works.
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russ_watters
#2
Apr7-05, 11:05 AM
Mentor
P: 22,252
Quote Quote by F Gump
My question is, IF these things were in japan after we droped the bomb, would they have residual radioactive dust still on them, in other words arent WWII collectibles from japan radilogicly contaminated?
Unless he physically rolled around in the dirt near ground-zero in one of those two cities, no (and even if he did, probably not).

Some info HERE.
Question 11. Are Hiroshima and Nagasaki still radioactive?

No. There are two ways radioactivity is produced from an atomic blast. The first is due to fallout of the fission products or the nuclear material itself, i.e., uranium or plutonium that contaminate the ground. (The same ground contamination occurred as a consequence of the Chernobyl accident.) The Hiroshima and Nagasaki bombs exploded at 500 to 600 m of altitude, then formed huge fireballs that rose with ascending air currents. Subsequently, the material cooled down and started to fall with rain. Because of the wind, the rain did not fall directly on the hypocenter but rather in the northwest region (Koi, Takasu area) of Hiroshima and the eastern region (Nishiyama area) of Nagasaki. Nowadays, the radioactivity is so miniscule that it is difficult to distinguish from trace amounts of radioactivity caused by atmospheric atomic-bomb tests.

Another way radioactivity is produced is by neutron irradiation of soil or buildings. (Neutrons comprise 10% or less of A-bomb radiation; nonradioactive materials become radioactive after absorbing neutrons. In contrast, gamma rays--which comprise the majority of A-bomb radiation--do not cause ground materials to become radioactive.) However, most of the radioactivity decayed very quickly so that it now takes months to measure the radioactivity using highly sensitive equipment. Despite miniscule levels, these measurements are currently utilized to estimate neutron doses released from the bombs.

In both cases, the residual radioactivity is far less than the dose received from background radiation; hence, there are no detectable effects on human health.
Others may be able to give more...
Morbius
#3
Apr7-05, 01:06 PM
Sci Advisor
P: 1,157
Quote Quote by F Gump
, in other words arent WWII collectibles from japan radilogicly contaminated?
F_Gump,

In a word - NO!!

The are a lot of things in your life that are much more radioactive than
Japanese collectables - including YOU.

Dr. Gregory Greenman
Physicist


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