WHAT’S A BEQUEREL? WHAT’S A SIEVERT?
Understanding units of radiation can be hopelessly confusing, resulting in potentially useful and informative data from a whole range of sources becoming a incomprehensible bunch of meaningless figures and symbols. Below is a short and simple explanation of the most commonly seen units of radiation.
Becquerel [Bq] or Curie [Ci]:
radiation emitted from a radioactive material (1 Ci = 3.7 × 1010 Bq)
Gray [Gy] or Rad [rad]:
radiation absorbed by another material (1Gy = 100 rad)
Sieverts [Sv]* or “roentgen equivalent in man”[rem]:
how badly radiation will damage biological tissue (1 Sv = 100 rem)
Grays and Rads can be converted to Rem and Sieverts once you know what kind of radiation you’re dealing with. E.g. Polonium-210 which occurs naturally emits alpha radiation which causes more biological tissue damage than Cesium-137’s gamma radiation. Absorption of equal amounts of both types, due to the higher number of Sieverts, would result in more damage from Polonium-210.
WHAT ARE BEQUERELS AND SIEVERTS?
Cesium-137 is product of nuclear fission. It only exists on our planet now because of our liking for blowing up nuclear bombs around the Earth. Consequently whilst prior to this there was none, there are now detectable, but safe, levels of Cesium-137 in all the oceans on our world.
WHAT DID THE FUKUSHIMA DAIICHI REACTOR RELEASE INTO THE OCEAN?
The Fukushima Nuclear disaster released radioactive isotopes into both the air and also the ocean which absorbed the isotopes raining down on it, in the area surrounding the power plant. These two pathways introduced An unsavoury cocktail consisting in the main of Iodine-131, Cesium-137, and Cesium-134, was in the process introduced and was also accompanied by a low percentage of Tellurium, Uranium and Strontium.
The exact amounts of each of these isotopes released into the ocean is not known, but estimates are roughly within the 538,100 terabecquerels (TBq) range. This is a higher level than that those at Three-Mile Island, but lower than Chernobyl levels, but does not include the contaminated groundwater that is also now known to be leaking into the sea.
Source: Deep Sea News : Kim Martini