04-13-2011, 01:31 PM
Let's run the numbers.
Looking at the Fukushima-shi rate: 2.1 microSieverts/hr.
24 hours in a day X 30 days in a month = 720 hours
If you stood outside for 24 hours a day (this kind of radiation is greatly decreased by the sheilding that is provided by common building materials) for the entire month, if the rate remains constant at that 2.1 microSieverts/hr. rate, you'd accumulate a dosage of 1512 microSieverts.
(2.1 x 24 x 30 = 1512)
A microSievert is 1/1000 of a milliSievert. So dividing by 1000 gives you 1.512 milliSiverts of total exposure for that time.
The amount of radiation that a nuclear plant worker is routinely allowed to be exposed to in a year is 50 milliSieverts. One has to think that there is some latitude in that number too.... that at a dosage of 50.000001 the person does not suddenly keel over and die or instantly get cancer. And remember that people have lifelong careers in the industry and aren't dropping like flies. So that is not some sort of "drop dead" (no pun intended) number.
To reach that 50 miliSievert level at the current dosage rate, someone would have to stand outside 24/7 per month for a total of 33 straight months......... 2.7 years!. Of course, no one is going to stant outside 24 hours a day 7 days a week for a month.
If a person was outside only 12 hours of the 24 hours in a day, that doubles the time to reach the exposure limit to almost 5 1/2 years.
Take something off for the radiation that does get through the building materials for the 12 hours of indoor time.... and you are still looking at a LONG time.
Is this normal.... absolutely NOT. But "doom and gloom, we're all gonna die, panic inducing"...... shoudn't be.
best,
.......................john
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