Radiation sickness - Revision history

RichardWSmith: /* Main types of damage */

2024-11-01T09:39:21Z

Main types of damage

RichardWSmith: /* Radiation weighting factors */ removed unneeded word.

2024-10-31T22:30:32Z

Radiation weighting factors: removed unneeded word.

RichardWSmith: /* Radiation measurements weighing biological damage */ Pointed out REM underestimates neutron damage.

2024-10-31T21:51:31Z

Radiation measurements weighing biological damage: Pointed out REM underestimates neutron damage.

RichardWSmith: /* Radiation weighting factors */

2024-10-31T21:49:53Z

Radiation weighting factors

RichardWSmith: /* Radiation weighting factors */ word choice

2024-10-31T21:47:49Z

Radiation weighting factors: word choice

RichardWSmith: /* Radiation weighting factors */ made title clearer

2024-10-31T21:40:55Z

Radiation weighting factors: made title clearer

RichardWSmith: /* Radiation weighting factors */

2024-10-31T21:38:38Z

Radiation weighting factors

RichardWSmith: /* Radiation measurements weighing biological damage */

2024-10-31T21:37:49Z

Radiation measurements weighing biological damage

RichardWSmith: /* Radiation measurements weighing biological damage */

2024-10-31T21:36:58Z

Radiation measurements weighing biological damage

RichardWSmith: /* Measurements independent of biological damage */

2024-10-31T21:35:14Z

Measurements independent of biological damage

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 There are 3 main types of radiation sickness:
-*Hematopoietic: This is damage to the blood cells.  A drop in red blood cells slows the flow of oxygen to cells, which have an increased metabolic burden, as they try to repair damage.  Drops in white blood cells make infections more likely.  A drop in platelets slows healing of bleeding (and the gut may well be bleeding from radiation damage).  Doses of 0.25 Sievert (Sv) = 25 Rad may cause clinically detectable decrease in blood production, but patients may not notice symptoms until the dose reaches 1.0 Sievert.
+*Hematopoietic: This is damage to the blood cells.  A drop in red blood cells slows the flow of oxygen to cells, which have an increased metabolic burden, as they try to repair damage.  Drops in white blood cells make infections more likely.  A drop in platelets slows healing of bleeding (and the gut may well be bleeding from radiation damage).  Doses of 0.25 Sievert = 25 RAD may cause clinically detectable decrease in blood production, but patients may not notice symptoms until the dose reaches 1.0 Sievert.
 *Gastronintestinal: The damage to the gut causes nausea, vomiting, loss of appetite, and abdominal pain (caused by internal bleeding).  Death usually follows from infection, rather than direct damage to the gut.  These symptoms typically occur at 4 Sv or higher.  (6 Sv for quick onset.)

← Older revision		Revision as of 22:30, 31 October 2024
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−	Basically neutrons have a weighting factor of about 2.5 for both low and high energies. For a fairly broad range of energies, the weighting factor ranges from 2.5 to 13. Then for a narrow spike around 1 MeV, the weighting factor ranges from ~~about~~ 13 to 20.5.	+	Basically neutrons have a weighting factor of about 2.5 for both low and high energies. For a fairly broad range of energies, the weighting factor ranges from 2.5 to 13. Then for a narrow spike around 1 MeV, the weighting factor ranges from 13 to 20.5.

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 The following radiation measurements have weightings to show how dangerous they are to living tissue.
-*The REM (Roentgen Equivalent Man) is an older measurement of radiation.  It has to be multiplied by a weighting factor depending on the type of radiation.
+*The REM (Roentgen Equivalent Man) is an older measurement of radiation.  It tends to underestimate neutron damage.
 *The RAD (Radiation Absorbed Dose) is like the REM, but with the various weighting factors already cooked in.  One RAD is equal to 100 ergs of energy absorbed per gram of material (tissue).  100 RAD is 1 Gy or 1 Sv.
 *A Gray (Gy) is a slightly out of date measure of radiation.  It has been replaced with the Sievert, but basically one Gray = 1 Sievert.

← Older revision		Revision as of 21:49, 31 October 2024
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	[[File: NeutronWeight MeV.png\|thumb\|600x500px\|top\| Figure 1: Neutron Weighting Factor to Energy in Mega electron Volts log scale]]		[[File: NeutronWeight MeV.png\|thumb\|600x500px\|top\| Figure 1: Neutron Weighting Factor to Energy in Mega electron Volts log scale]]
−

	(For the neutron function, see Figure 1, or Equation 4.3, on page 66 of the English version of the 2007 Recommendations of the International Commission on Radiological Protection, ICRP Publication 103, published in 2007.)		(For the neutron function, see Figure 1, or Equation 4.3, on page 66 of the English version of the 2007 Recommendations of the International Commission on Radiological Protection, ICRP Publication 103, published in 2007.)

← Older revision		Revision as of 21:47, 31 October 2024
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	(For the neutron function, see Figure 1, or Equation 4.3, on page 66 of the English version of the 2007 Recommendations of the International Commission on Radiological Protection, ICRP Publication 103, published in 2007.)		(For the neutron function, see Figure 1, or Equation 4.3, on page 66 of the English version of the 2007 Recommendations of the International Commission on Radiological Protection, ICRP Publication 103, published in 2007.)

−	Basically neutrons have a weighting factor of about 2.5 for both low and high energies. For a fairly broad ~~area~~ of energies, the weighting factor ranges from 2.5 to 13. Then for a narrow spike around 1 MeV, the weighting factor ranges from about 13 to 20.5.	+
		+	Basically neutrons have a weighting factor of about 2.5 for both low and high energies. For a fairly broad range of energies, the weighting factor ranges from 2.5 to 13. Then for a narrow spike around 1 MeV, the weighting factor ranges from about 13 to 20.5.

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 |}
-[[File: NeutronWeight MeV.png|thumb|600x500px|top| Figure 1: Neutron Weighting Factor --- Energy MeV log scale]]
+[[File: NeutronWeight MeV.png|thumb|600x500px|top| Figure 1: Neutron Weighting Factor to Energy in Mega electron Volts log scale]]
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 Basically neutrons have a weighting factor of about 2.5 for both low and high energies.  For a fairly broad area of energies, the weighting factor ranges from 2.5 to 13.  Then for a narrow spike around 1 MeV, the weighting factor ranges from about 13 to 20.5.
 Some people approximate this by saying the weighting factor is around 10, but as can be seen, this is an oversimplification.  See the figure to the right.

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 (For the neutron function, see Figure 1, or Equation 4.3, on page 66 of the English version of the 2007 Recommendations of the International Commission on Radiological Protection, ICRP Publication 103, published in 2007.)
-Basically neutrons have a weighting factor of about 2.5 for both low and high energies.  For a fairly broad area of energies, the weighting factor ranges from 2.5 to 13.  Then for a narrow spike around 1 MeV, the weighting factor ranges from about 13 to 20.5.  Some people approximate this by saying the weighting factor is around 10, but as can be seen, this is an oversimplification.  See the figure to the right.
+Basically neutrons have a weighting factor of about 2.5 for both low and high energies.  For a fairly broad area of energies, the weighting factor ranges from 2.5 to 13.  Then for a narrow spike around 1 MeV, the weighting factor ranges from about 13 to 20.5.
 ===Radiation measurements weighing biological damage===

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 *One decay per second is 1 Becquerel (Bq).  This is a TINY measure of radiation, so small that it is not much use in the real world, but scientists might use it when measuring very, very small radiation levels.
 *A Curie (Ci) is defined as 37 billion Becquerel.  This is a dangerous amount of radiation, and if you are near something this radioactive, you would want to leave soon.
-*The Roentgen (R) measures how much ionization is in the air. (This is a pretty indirect way to measure radiation, but it does has the advantage that it measure [[Ionizing Radiation]] which is what is dangerous to us.)  1 R is about 0.01 Sv.  (1 Sv is getting to the "getting dangerous" range, so it would take 100 hours of 1 R / hour exposure to reach this level.)  Whereas, 1 R per second is a "get out of there right now!" level of radiation.
+*The Roentgen (R) measures how much ionization is in the air. (This is a pretty indirect way to measure radiation, but it does has the advantage that it measures [[Ionizing Radiation]] which is what is dangerous to us.)  1 R is about 0.01 Sv.  (1 Sv is getting to the "getting dangerous" range, so it would take 100 hours of 1 R / hour exposure to reach this level.)  Whereas, 1 R per second is a "get out of there right now!" level of radiation.
 Radiation comes in various types, and Bq just counts 'particles'.  So a particle with very low energy (which is not dangerous) counts the same as high energy particles.