> Basic conversions:
> 1 gray (Gy) = 100 rad
> 1 rad = 10 milligray (mGy)
> 1 sievert (Sv) = 1,000 millisieverts (mSv) = 1,000,000 microsieverts (μSv)
> 1 sievert = 100 rem
> 1 becquerel (Bq) = 1 count per second (cps)
> 1 curie = 37,000,000,000 becquerel = 37 Gigabecquerels (GBq)
> Hope this helps,
> I still get confused with all of the different terms/standards such as
> gray, rad, sievert, Gq, curie, Rem and CPMs.
> - Arlen
As Eisenhower said, keep the public confused about fusion and fission. This applies to units of measurement, too. The only reason the industry wants to use Grays instead of rads is the numbers are lower, which seems lower to the lay public. Linguistic detoxification.
1 Gray = 100 rads
1 Sievert = 100 rems (the amount absorbed, adjusted for type of radiation - alpha, beta, gamma - I think).
Bq - Becquerel - one disintegration per second
CPM is in the Becquerel range (per minute, not per second).
Curie - 37 billion Bq - equivalent to one gram of radium (a very large amount)
From another alert:
I had been wondering when the Obama administration would get around to promoting its own food irradiation regulations. The FDA on November 30, 2012 published a rule allowing for 50% more radiation exposure to meat. Previously the level was 300,000 rads, now 450,000 rads will be allowed. We get one tenth of a rad per year from normal background dose, another tenth from fallout (from reactors and bombs), on average. 600 rads is a lethal dose for everyone, if a full body exposure. The industry is being cute about describing the dose, using a "Gray" instead of a "rad" since using "Gray" means a smaller prefix can be used. One "Gray" equals 100 rads. Since food irradiation uses doses that makes the neutron bomb look like a dental x-ray, they use kiloGray or kGy which is incomprehensible for 99.9999% of people. Calling the new permitted dose 4.5 kGy seems smaller than calling it 450,000 rads since "4.5" is a smaller number than "450,000."
The Carter administration refused to permit food irradiation.
Reagan's people approved food irradiation. Clinton expanded it. Bush expanded it. And now Obama has expanded it.
Note: exposing food to high levels of radiation does not make it radioactive (the fake debate used by the industry to dismiss concerns). Instead, it changes the chemistry of the food, turning vitamins into compounds that are not quite vitamins. These "radiolytic products" are the toxic impacts, apart from the environmental and occupational health concerns of using large radiation sources to treat the meat. Also recommended is learning about the profound difference between using microwaves (radar) to heat food and using gamma radiation (at the other end of the electromagnetic spectrum). Microwave sources do not "nuke" food, they have their own problems but it is not food irradiation.
One good thing is the food irradiation industry during the Reagan years was hoping for 1,000 irradiators in the US by the year 2000, which did not happen. This disaster was prevented because few food companies were willing to publicize their interest in exposing their products to nuclear radiation. But the practice continues at a small level, unlabeled and unmonitored.
Being involved in the anti-food irradiation movement in the 1980s inspired me to learn about organic food, food additives, gardening, vegetarianism, energy inputs to agriculture and food policies that permit poisons in the food supply.
The FDA Federal Register notice is attached as a PDF file.
It's another reason I'm glad I voted "None of the Above"
"The more things change the more they stay the same."
-- French proverb