A lot of ways of expressing doses are being used that span different periods of time amongst other things, and as it's not easy gauging the radiological effect at the best of times (e.g eating or breathing the stuff is really bad), here's a comparisons list I made. The most common unit currently being used for the radiological effect on humans in the media is the sievert.
Sievert (Sv) "equivalent dose" (old measure was rem). 1 Sv = 1 J/kg = 1 m^2/s^2 = 100 rem
Prefixes
m = milli = 1*10^-3
μ = micro = 1*10^-6
n = nano = 1*10^-9
p = pico = 1*10^-12
Watch out for milli and micro as they are easily confused, especially their respective prefix symbols, and to top it all when copying μ, it pastes here as an m! Hope I caught them all. Maybe μ still displays here as an m in your browser.
Single dose
0.1 μSv = Banana
185 μSv = Flight from Tokyo to London & back
0.04 mSv = Chest x-ray = 2 to 3 years of background radiation
1-3 Sv = Recovery probable but not assured
3-6 Sv = Death probable if not treated
10+ Sv = Incapacitation and death
Per hour
6 μSv / hour = Aircraft flight
1 Sv / hour = Nausea
2.5 Sv / hour = Hair loss and possible death
Per year
0.4 mSv / year = Radioactivity of a human
1 mSv / year = Max recommended exposure for public from human sources
2 mSv / year = Natural background (up to 50 mSv in some countries) = 270×10^-6 Gy ?
13 mSv / year = Smoking 30 a day for a year
20 mSv / year = Max recommended for radiation workers
100 mSv / year = Rate above which cancer rates seen to increase
[ 1mSv = 0.001Sv or 1×10^-3 Sv, 1μSv=0.000001Sv or 1×10^-6 Sv ]
Banana equivalent dose =3520pCi/kg = 130Bq/kg. Or 520pCi / banana = 5.2×10^-10Ci = 19 Bq/banana. 365 bananas = 36uSv
Brazil nuts = 444 Bq/kg
Hopefully we will not have a need to reference a whole seivert.
Additions or corrections welcome.
Other units:
Becquerel (Bq) decays/second. 1 Bq = 2.7×10^−11 Ci. See curie
curie (Ci), a unit of radioactivity
1 Ci = 3.7×10^10 decays/second = 3.7×10^10 Becquerel (Bq) ~ 1 gram of radium
A radiotherapy machine may contain 1000Ci of radioisotope such as caesium-137 or Cobalt-60 = serious health effects after a few minutes exposure. Human body contains ~ 0.1 μCi of naturally occurring potassium-40 (1 μCi = 3.7×10^4 disintegrations/second)
Gray (Gy) "absorbed dose". J/kg (as with the Sv). 1Gy = 100 RAD
Not a good biological measure. For electron & photon radiation 1 Gy = 1 Sv
Its non-SI unit was the RAD.
Badly vented house can give 6μGy / hour
Maximum level allowed in working environment = 20μGy / hour
RAD = 0.01 Gy. see Gray
rem = 0.01 Sv. See Sievert
Here's a chart that shows dosages in a slightly different way:
Sievert (Sv) "equivalent dose" (old measure was rem). 1 Sv = 1 J/kg = 1 m^2/s^2 = 100 rem
Prefixes
m = milli = 1*10^-3
μ = micro = 1*10^-6
n = nano = 1*10^-9
p = pico = 1*10^-12
Watch out for milli and micro as they are easily confused, especially their respective prefix symbols, and to top it all when copying μ, it pastes here as an m! Hope I caught them all. Maybe μ still displays here as an m in your browser.
Single dose
0.1 μSv = Banana
185 μSv = Flight from Tokyo to London & back
0.04 mSv = Chest x-ray = 2 to 3 years of background radiation
1-3 Sv = Recovery probable but not assured
3-6 Sv = Death probable if not treated
10+ Sv = Incapacitation and death
Per hour
6 μSv / hour = Aircraft flight
1 Sv / hour = Nausea
2.5 Sv / hour = Hair loss and possible death
Per year
0.4 mSv / year = Radioactivity of a human
1 mSv / year = Max recommended exposure for public from human sources
2 mSv / year = Natural background (up to 50 mSv in some countries) = 270×10^-6 Gy ?
13 mSv / year = Smoking 30 a day for a year
20 mSv / year = Max recommended for radiation workers
100 mSv / year = Rate above which cancer rates seen to increase
[ 1mSv = 0.001Sv or 1×10^-3 Sv, 1μSv=0.000001Sv or 1×10^-6 Sv ]
Banana equivalent dose =3520pCi/kg = 130Bq/kg. Or 520pCi / banana = 5.2×10^-10Ci = 19 Bq/banana. 365 bananas = 36uSv
Brazil nuts = 444 Bq/kg
Hopefully we will not have a need to reference a whole seivert.
Additions or corrections welcome.
Other units:
Becquerel (Bq) decays/second. 1 Bq = 2.7×10^−11 Ci. See curie
curie (Ci), a unit of radioactivity
1 Ci = 3.7×10^10 decays/second = 3.7×10^10 Becquerel (Bq) ~ 1 gram of radium
A radiotherapy machine may contain 1000Ci of radioisotope such as caesium-137 or Cobalt-60 = serious health effects after a few minutes exposure. Human body contains ~ 0.1 μCi of naturally occurring potassium-40 (1 μCi = 3.7×10^4 disintegrations/second)
Gray (Gy) "absorbed dose". J/kg (as with the Sv). 1Gy = 100 RAD
Not a good biological measure. For electron & photon radiation 1 Gy = 1 Sv
Its non-SI unit was the RAD.
Badly vented house can give 6μGy / hour
Maximum level allowed in working environment = 20μGy / hour
RAD = 0.01 Gy. see Gray
rem = 0.01 Sv. See Sievert
Here's a chart that shows dosages in a slightly different way:
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