Radiation is emitted from radioactive materials. Radioactive materials originated from nuclear plant explosions are ... sort of very small dust. I think... They are carried by wind and fall on the ground, roof, vegetable... anywhere.
Tokyo is more 200km away from Fukushima nuclear plants, the wind was flowing toward to the sea when plants exploded, so radioactive materials seemed to take a few days from Fukushima to Tokyo.
When we had rain, lots of dust in the higher place in the air fell with rain.
So after rain, radioactive material levels showed higher number.
Unfortunately we can not get away from these dust. We can breath radioactive materials in the air and and keep them in lung, we can drink the water containing radioactive materials, we can eat vegetable on which radioactive materials stick. So do livestock. So do fish. Thus creature of top of food chain can ingest condensed radioactive food.
By the way, I purchased a lot of mask before earthquake as a preparation of hay fever season. I have pollen allergy like typical Japanese. I heard radioactive materials are bigger than virus and smaller than pollen. (I am looking for technical trustable data about this.). So mask for virus will be helpful to reduce inhalation of radioactive materials.
My masks don't work for reducing radioactive materials, but pollen allergy people know how to reduce the effect of fallout. I heard following way are effective, at least they would bring better result than do nothing. Radiation is invisible and it will show their aftermath after 10 years, 20 yeas ...... But pollen allergy people detect immediately pollen existence by one's snotty nose, eye itch, etc. etc....
don't open wind too much
clean up the dust on coat before coming into the house
wear appropriate mask
wear appropriate glasses
Radioactive material level of fallout in Tokyo / day
|2011/04/03 9:00 - 2011/04/04 9:00||20.0||17.5|
|2011/04/02 9:00 - 2011/04/03 9:00||(ND)||8.03|
|2011/04/01 9:00 - 2011/04/02 9:00||(ND)||14.5|
|2011/03/31 9:00 - 2011/04/01 9:00||37.6||26.1|
|2011/03/30 9:00 - 2011/03/31 9:00||50.1||68.4|
|2011/03/29 9:00 - 2011/03/30 9:00||21.3||5.35|
|2011/03/28 9:00 - 2011/03/29 9:00||36.9||18.1|
|2011/03/27 9:00 - 2011/03/28 9:00||45.5||5.52|
|2011/03/26 9:00 - 2011/03/27 9:00||101||35.9|
|2011/03/25 9:00 - 2011/03/26 9:00||217||12.2|
|2011/03/24 9:00 - 2011/03/25 9:00||173||36.9|
|2011/03/23 9:00 - 2011/03/24 9:00||12790||155||rain|
|2011/03/22 9:00 - 2011/03/23 9:00||35700||335||rain|
|2011/03/21 9:00 - 2011/03/22 9:00||32300||5300||rain|
|2011/03/20 9:00 - 2011/03/21 9:00||2880||561||rain|
|2011/03/19 9:00 - 2011/03/20 9:00||39.8||(ND)|
|2011/03/18 9:00 - 2011/03/19 9:00||51.4||(ND)|