Sievert（Sv）

　When the human body received radioactive rays;
the unit that is used as a ruler measuring the degree of the influence.

5% fatal dose of radioactivity 2Sv,
50% fatal dose of radioactivity 4Sv,
100% fatal dose of radioactivity 7Sv.
For the radiation exposure less than the degree 200 millimeters sievert
that 250 millimeters sievert hair falls out,
there is no acute clinical symptom

It is a drop 420 millimeters sievert with a radiation dose of 8,
217 an hour microsievert (8.217 millimeters sievert)
with the monitoring post of the front gate
of the first Fukushima nuclear power generation afterwards
at 3/15 measurement about 10:00
at best time with the unit No. measurement
Fukushima nuclear power generation 4 at 8:31 a.m. for 15 days

1000 microsievert =1 millimeters sievert.
1Sv (Sv) =1,000 millimeters sievert (mSv) =100 ten thousand microsievert（μ Sv）