System Of Radiation Protection Overview

2019-11-04T15:01:12Z

Karen Clement: /* Fundamental Principles of Radiological Protection */

System Of Radiation Protection Overview

2019-11-04T15:00:29Z

Karen Clement: /* Fundamental Principles of Radiological Protection */

File:SystemofProtectionFoundations.jpg

2019-11-04T14:59:21Z

Karen Clement: File uploaded with MsUpload

File uploaded with MsUpload

Radon For Governments and Employers

2019-10-31T14:26:57Z

Karen Clement:

[[#top| ]]
__FORCETOC__
[[File:ICRPGuide.JPG|150px|thumb|right|link=Guide_to_Radon_demo|Take me back to the ICRP's [[Guide_to_Radon|Guide to Radon]]!]]

==Radon Recommendations for Authorities==
 
{{#ev:youtube|https://youtu.be/HryzrFjU4fQ|500|right|A message on public health and radon from the National Collaborating Centre for Environmental Health in Canada|frame}}
National authorities have an important role to play in reducing radon levels.

National authorities should:
*have a reasonable understanding of indoor radon exposures across the country
*develop a national radon protection strategy

The '''national radon protection strategy''' should be straightforward and realistic, and be considered in conjunction with other public health policies, such as energy saving, non-smoking, and indoor air quality. It should address exposures in new and existing buildings, aiming to reduce:
*the overall exposure of the general population
*the highest individual exposures

To help guide action, '''authorities should set a national reference level''' for indoor radon levels:
*ICRP recommends setting a national reference level [[Fundamental Principles of Radiological Protection|'''as low as reasonably achievable''']] in the range of 100–300 [[Radon: Units of Measure|Bq/m3]].
*WHO guidance is basically the same: a national reference level of 100 [[Radon: Units of Measure|Bq/m3]] is recommended, and wherever this is not possible, the chosen level should not exceed 300 [[Radon: Units of Measure|Bq/m3]].

===Quotes From Publications===
Radon Protection Strategy:[[ICRP Publication 126|Publication 126]]<ref name="Pub126">[[ICRP Publication 126]] Radiological Protection against Radon Exposure Ann ICRP 43(3) 2014.</ref> paragraphs 41-45

''…Prevention of radon exposure is most relevant in new buildings. The implementation of preventive measures in new and renovated buildings provides a good partial solution… This also helps to develop awareness amongst professionals involved in the construction sector.''

''Remediation in existing buildings is also often appropriate in buildings with high radon concentrations. In such situations, there may be a primary source of radon ingress, and radon levels can often be reduced by a factor exceeding 10.
… the aim should be to reduce both the overall risk for the population and, for the sake of equity, the highest individual exposures to levels that are as low as reasonably achievable…''

''…The radon protection strategy should be properly scaled, with other health hazards and priorities identified in the country taken into account. Furthermore, comparison and integration between the radon protection strategy and other public health policies, such as non-smoking and indoor air quality policies, should be sought in order to avoid inconsistencies and achieve better effectiveness.''

''Considering the ubiquity of radon exposure, and the multiplicity and diversity of situations and decision makers, a straightforward, realistic, and integrated radon protection strategy, addressing most situations with the same approach, is appropriate. It must be supported and implemented on a long-term, potentially permanent basis, and involve all the relevant stakeholders. ''

National reference Level: [[ICRP Publication 126|Publication 126]]<ref name="Pub126">[[ICRP Publication 126]] Radiological Protection against Radon Exposure Ann ICRP 43(3) 2014.</ref> paragraphs 84, 76, and 86

''The first step is to characterise the exposure situation of individuals and the general population in the country, as well as other relevant economic and societal criteria, and the practicability of mitigating or preventing the exposure. … Many factors such as mean radon concentration and radon distribution, number of existing homes with high radon levels, etc. should be taken into consideration.''

''… The Commission strongly encourages … a national derived reference level that is as low as reasonably achievable in the range of 100–300 Bqm-3…''

''The value of the national derived reference level for radon exposure should be reviewed periodically to ensure that it remains appropriate. ''

'''[[#Top|Back to Top]]'''

==Radon Recommendations for Workplaces==
 
'''Employers have an important role to play in reducing radon levels.'''

In most workplaces, exposure to radon is treated the same as in other buildings, by taking measurements, comparing radon levels to [[Radon For Governments and Employers#Radon Recommendations for Authorities|national reference levels for indoor radon]], and taking action if necessary.

In some workplaces, where levels are above the [[Radon For Governments and Employers#Radon Recommendations for Authorities|national reference levels for indoor radon]], doses to workers should be assessed, and protection should be [[Fundamental Principles of Radiological Protection|optimised]].

Where, despite all reasonable measures, doses to workers may exceed 10 mSv per year, employers should use protection requirements for [[Exposure Categories and Situations|occupational exposure]].

Requirements for [[Exposure Categories and Situations|occupational exposure]] also apply in a few specific workplaces. Which ones is often decided by the national authority. A common example is uranium mines.

The occupational [[Dose Limits|dose limit]] should apply when the national authorities consider that the radon exposure should be managed as a [[Exposure Categories and Situations|planned exposure situation]].

'''[[#Top|Back to Top]]'''

==Calculating Radon Doses==

'''Radon levels (in [[Radon: Units of Measure|Bq/m3]]) are used directly to control radon levels in homes and most workplaces. However, sometimes it is necessary to calculate the effective dose due to radon exposure for some workplaces.'''

ICRP develops [[ICRPædia Guide to Dose Coefficients|dose coefficients]] to simplify the calculation of [[Absorbed, Equivalent, and Effective Dose|equivalent dose and effective dose]] for inhaled or ingested radionuclides.

In simplest terms, calculating the dose from inhaling radon involves multiplying the average radon level (e.g. in [[Radon: Units of Measure|Bq/m3]]) by the time spent, and the right [[ICRPædia Guide to Dose Coefficients|dose coefficient]].

<center> ''[[Absorbed, Equivalent, and Effective Dose|Effective dose]] = radon level × time × [[ICRPædia Guide to Dose Coefficients|dose coefficient]]'' </center>

Using the [[ICRPædia Guide to Dose Coefficients|dose coefficient]] for most circumstances of occupational exposure, breathing air with 50 [[Radon: Units of Measure|Bq/m3]] of radon (a typical worldwide value in buildings) for one year at work (2000 hours) gives an [[Absorbed, Equivalent, and Effective Dose|effective dose]] of 0.7 mSv. For working indoors doing substantial physical activity, or for exposures in tourist caves, the recommended [[ICRPædia Guide to Dose Coefficients|dose coefficient]] is higher, so breathing air with 50 [[Radon: Units of Measure|Bq/m3]] of radon for one year at work gives an [[Absorbed, Equivalent, and Effective Dose|effective dose]] of 1.4 mSv.

'''[[#Top|Back to Top]]'''

[[File:ICRPGuide.JPG|50px|link=Guide_to_Radon]]Take me back to the ICRP's [[Guide_to_Radon|Guide to Radon]]!

==More In-Depth Information==
 

If you are looking for something more extensive look no further below are a collection of related links and articles that can provide more information on this topic!
{| class="wikitable"
|-
| Expert Summary of ICRP Recommendations on Radon
| [[Media:ICRPRadonSummary.pdf|ICRP Radon Summary]]
|-
| Lung Cancer Risk from Radon and Progeny and Statement on Radon
| [[ICRP Publication 115]]
|-
| Radiological Protection against Radon Exposure
| [[ICRP Publication 126]]
|-
| Occupational Intakes of Radionuclides: Part 3
| [[ICRP Publication 137]]
|}
'''[[#Top|Back to Top]]'''

==References==
 
<references/>

General Information on Radon

2019-10-30T12:41:02Z

Karen Clement:

[[#top| ]]
__FORCETOC__
[[File:ICRPGuide.JPG|150px|thumb|right|link=Guide_to_Radon|Take me back to the ICRP's [[Guide_to_Radon|Guide to Radon]]!]]

==What is Radon?==
 
[[file:Radon_PTable.jpg|200px|thumb]]
 '''Radon (chemical symbol: Rn) is a natural part of the environment. It is a radioactive gas that comes mainly from soil and rock, and is a normal part of the air we breathe.''' 

Radon can also come from water and building materials, but the amount is usually very small.
Radon cannot be seen, and has no smell. The only way to know how much radon is in the air is to [[Radon For Homeowners and Residents#Measuring and Reducing Radon Levels in your Home|measure it]].

Radon makes up the largest part of natural [[Sources of Radiation Exposure]].

There is usually less radon outdoors than indoors, since radon can concentrate in enclosed spaces. Exposure to radon outdoors is generally not an issue, so we normally focus on [[Radon For Homeowners and Residents#Exposure to Radon at Home|Exposure to Radon at Home]] and in indoor workplaces.

Radon is the second leading cause of lung cancer after smoking. Exposure to higher levels of radon for a long time can increase your [[General Information on Radon#Risk of Exposure to Radon|risk of lung cancer]].

Information on measuring and, if necessary, reducing radon levels, is available for [[Radon For Homeowners and Residents#Measuring and Reducing Radon Levels in your Home|homeowners]], [[Radon For Governments and Employers#Radon Recommendations for Workplaces|businesses]], and [[Radon For Governments and Employers#Radon Recommendations for Authorities|government authorities]].

'''[[#Top|Back to Top]]'''

==Risk of Exposure to Radon==
 [[file:RiskOfExposureToRadon.jpg|370px|thumb]]
There is strong evidence that exposure to radon can cause lung cancer. Radon exposure is the second leading cause of lung cancer after smoking.

Smokers are more at risk from radon exposure than non-smokers. A lifetime of exposure to radon at 100 [[Radon: Units of Measure|Bq/m3]] increases the risk of lung cancer by 0.1% for non-smokers, and 2% for smokers.

More precisely, for an average radon concentration of 100 [[Radon: Units of Measure|Bq/m3]], the lifetime risk of lung cancer for non-smokers is 0.5% (compared with a risk of 0.4% in the absence of radon). For lifelong smokers, the risk is 12% (compared with a risk of 10% in the absence of radon).

===From the WHO Factsheet on Indoor Radon===

''"Radon is the most important cause of lung cancer after smoking. It is estimated that radon causes between 3–14% of all lung cancers in a country, depending on the average radon level and the smoking prevalence in a country.”

''“… the risk of lung cancer increases … with increasing radon exposure.” ''

{|
|style="border: 1px solid #4682B4;" | The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) is the leading international body on radiation levels and effects. Visit the [http://www.unscear.org/ UNSCEAR website] or read the UNEP report on [https://wedocs.unep.org/handle/20.500.11822/7790;jsessionid=E71B4A7CFB4A79AB88CAC19654B2CBF7 "Radiation Effects and Sources"] based on UNSCEAR work to learn more
|}

===Quotes from Publications===

Lung Cancer: [[ICRP Publication 115|Publication 115]]<ref name="Pub115">[[ICRP Publication 115]] Lung Cancer Risk from Radon and Progeny and Statement on Radon Ann ICRP 40(1) 2010.</ref> paragraph 55

''… There is compelling evidence from cohort studies of underground miners and from case–control studies of residential radon exposures that radon and its progeny can cause lung cancer…''

''… The cumulative risk of lung cancer up to 75 years of age for lifelong non-smokers is estimated to be 0.4%, 0.5%, and 0.7% for radon activity concentrations of 0, 100, and 400 Bq/m3, respectively…''

''…The cumulative risks of lung cancer for lifelong smokers by 75 years of age are close to 10%, 12%, and 16% for radon activity concentrations of 0, 100, and 400 Bq/m3, respectively…''

''… Cigarette smoking remains the most important cause of lung cancer… ''

Other Cancers: [[ICRP Publication 115|Publication 115]]<ref name="Pub115">[[ICRP Publication 115]] Lung Cancer Risk from Radon and Progeny and Statement on Radon Ann ICRP 40(1) 2010.</ref> paragraph 39

''… review of the available epidemiological evidence shows no consistent evidence for an association between radon concentration and cancer, other than lung cancer.''

'''[[#Top|Back to Top]]'''

==Units of Measure==
 
===Radon Measurements===
A becquerel is a measure of radioactivity. One becquerel (Bq) is equal to one radioactive decay per second.

Radon concentrations in air are usually measured in becquerels per cubic meter (Bq/m3). That’s the amount of radon (becquerels) in a volume of air (cubic metre).

Worldwide, the average radon concentration in outdoor air is around 10 Bq/m3.

Some countries still use older units of picocuries per litre (pCi/L). 10 Bq/m3 = 0.27 pCi/L.

===Potential Alpha Energy Concentration===
In some circumstances, it’s more important to measure the level of radon progeny instead of the radon itself, specifically the Potential Alpha Energy Concentration (PAEC). This is the sum of the alpha particle decay energy of all the short-lived progeny of radon in a volume of air. The SI unit is joule per cubic metre (J m-3).

Historically, PAEC was measured in units of Working Levels (WL).
1 WL= 2.08 x 10-5J m-3

===Quotes from ICRP===

[[ICRP Publication 65|Publication 65]]<ref name="Pub065">[[ICRP Publication 65]] Protection Against Radon-222 at Home and at Work - Ann ICRP 23(2) 1993.</ref> paragraphs 15-22

''The potential alpha energy … of an atom in the decay chain of radon is the total alpha energy emitted during the decay of this atom to stable 210Pb…. The potential alpha energy concentration…of any mixture of short-lived radon progeny in air is the sum of the potential alpha energy of these atoms present per unit volume of air.… This quantity is expressed in the SI unit J m-3….''

''The potential alpha energy concentration … can be also expressed in terms of the so-called equilibrium equivalent concentration of … radon. The equilibrium equivalent concentration, corresponding to a non-equilibrium mixture of radon progeny in air, is the activity concentration of radon in radioactive equilibrium with its short-lived progeny that has the same potential alpha energy concentration … as the actual non-equilibrium mixture. The SI unit of the equilibrium equivalent concentration is Bq m-3….''

''… exposure … to radon progeny is defined as the time integral of the potential alpha energy concentration in air… The unit … is J h m-3 … [or] the historical unit Working Level Month (WLM) … 1 WLM = 3.54 mJ h m-3… ''

'''[[#Top|Back to Top]]'''

[[File:ICRPGuide.JPG|50px|link=Guide_to_Radon]]Take me back to the ICRP's [[Guide_to_Radon|Guide to Radon]]!

==More In-Depth Information==
 

If you are looking for something more extensive look no further below are a collection of related links and articles that can provide more information on this topic!

===Risk of Exposure to Radon===
{| class="wikitable"
|-
| Expert Summary of ICRP Recommendations on Radon
| [[Media:ICRPRadonSummary.pdf|ICRP Radon Summary]]
|-
| Lung Cancer Risk from Radon and Progeny and Statement on Radon
| [[ICRP Publication 115]]
|-
| Radiological Protection against Radon Exposure
| [[ICRP Publication 126]]
|-
| WHO Factsheet on Indoor Radon
| [http://www.who.int/mediacentre/factsheets/fs291/en/ www.who.int]
|-
| WHO Handbook on Indoor Radon
| [http://apps.who.int/iris/bitstream/10665/44149/1/9789241547673_eng.pdf Handbook]
|-
| UNEP report on Radiation Effects and Sources
| [https://wedocs.unep.org/handle/20.500.11822/7790;jsessionid=E71B4A7CFB4A79AB88CAC19654B2CBF7 https://wedocs.unep.org/]
|}
'''[[#Top|Back to Top]]'''

==References==
 
<references/>

System of radiation protection module 2

2019-10-28T13:18:59Z

Karen Clement: /* Exposure Categories and Situations */

[[#top| ]]
__FORCETOC__
[[File:ICRPGuide.JPG|150px|thumb|right|link=Guide_to_the_System_of_Radiological_Protection|Take me back to the ICRP's [[Guide_to_the_System_of_Radiological_Protection|Guide to the System of Radiological Protection]]!]]

==Exposure Categories and Situations==
 
'''Categories of exposure and exposure situations are used to consider how best to approach radiological protection in different circumstances.'''

Exposure Categories are: occupational, public, and medical.

Exposure Situations are: planned, existing, and emergency.

Categories and Situations are considered together to help guide the best approach to radiological protection in a particular circumstance.

{| class="wikitable"
| style="height: 80px;" |
! [[Image: OccupationalE.png |40px|link=]]

[[Glossary#Occupational Exposure | Occupational Exposure]]

''Exposure of workers incurred as a result of their work''

! [[Image: PublicE.png|40px|link=]]

[[Glossary#Public Exposure | Public Exposure]]

''Exposure of members of the public other than occupational and medical exposures, and not including the normal local natural background radiation''

! [[Image: MedicalE.png |40px|link=]]

[[Glossary#Medical Exposure | Medical Exposure]]

''Exposure of patients as part of their diagnosis or treatment, volunteers helping in the support and comfort of patients, and volunteers in biomedical research
''

|-
! [[Image: PlannedES.png |40px|link=]]

[[Glossary#Planned Exposure Situation | Planned Exposure Situation]]

''Situations where radiological protection can be planned in advance, and exposures can be reasonably predicted''

| style="height: 80px;" | e.g. working in a hospital, uranium mine, or nuclear power plant
| e.g. visiting a hospital, living near a nuclear power plant
| e.g. getting an x-ray, CT scan, or radiation treatment
|-
! [[Image: ExistingES.png |40px|link=]]

[[Glossary#Existing Exposure Situation | Existing Exposure Situation]]

''Situations that already exist when a decision on control has to be taken''

| style="height: 80px;" | e.g. aircrew and astronauts exposed to [[Cosmic Radiation in Aviation | cosmic radiation]]
| e.g. [[Exposure to Radon at Home | radon gas in the home]]
| n/a
|-
! [[Image: EmergencyES.png |40px|link=]]

[[Glossary#Emergency Exposure Situation | Emergency Exposure Situation]]

''Unexpected situations that may require urgent protective actions''

| style="height: 80px;" | e.g. in the immediate response to an accident
| e.g. during a major accident
| n/a
|}

'''[[#Top|Back to Top]]'''

==Radiation Dose==

Radiation dose is a measure of the amount of exposure to radiation. There are three kinds of dose in radiological protection. ''Absorbed dose'' is a measureable, physical quantity, while ''equivalent dose'' and ''effective dose'' are specifically for radiological protection purposes.

''Effective dose'' in particular is a central feature of radiological protection. It sums up any number of different exposures into a single number that reflects, in a general way, the overall risk. The concept may be complex, but it makes radiological protection practical to implement.

===Absorbed Dose===
Absorbed dose is the amount of energy deposited by radiation in a mass.
The mass can be anything: water, rock, air, people, etc.
Absorbed dose is expressed in milligrays (mGy).

Absorbed dose is a measurable, physical quantity. It is expressed in grays (Gy), or, more frequently milligrays (mGy), which are 1/1000th of a gray. 1 gray = 1 joule of energy deposited in 1 kilogram of material i.e. 1 Gy = 1 J/kg

===Equivalent Dose===
Equivalent dose is calculated for individual organs.
It is based on the absorbed dose to an organ, adjusted to account for the effectiveness of the type of radiation.
Equivalent dose is expressed in millisieverts (mSv) to an organ.

Equivalent dose = absorbed Dose multiplied the appropriate radiation weighting factor. The radiation weighting factors are needed because different types of radiation (like alpha, beta, gamma, and neutrons) can have different effects even if the absorbed dose is the same. Equivalent dose is expressed in sieverts (Sv), or, more frequently, millisieverts (mSv) which are 1/1000th of a sievert, and the organ should always be specified (for example "25 mSv to the skin"). In the simplest cases, for gamma (photon) and beta (electron) radiation, the radiation weighting factor is 1, and therefore, for example, an absorbed dose of 1 mGy in an organ equals an equivalent dose of 1 mSv to that organ.

===Effective Dose===
Effective dose is calculated for the whole body. It is sometimes called whole-body dose.
It is the addition of equivalent doses to all organs, each adjusted to account for the sensitivity of the organ to radiation.
Effective dose is expressed in millisieverts (mSv).

Effective dose = sum for all organs of (equivalent dose to the organ times the appropriate tissue weighting factor)
The tissue weighting factors are needed because different organs have different levels of sensitivity to radiation, even if the equivalent dose is the same. Effective dose is expressed in sieverts (Sv), or, more frequently, millisieverts (mSv) which are 1/1000th of a sievert. This is the most frequently used dose in radiological protection. Unless you see mention of a specific organ, a "dose" in Sv or mSv is the effective dose. In the simplest cases, for uniform whole-body exposure to gamma (photon) or beta (electron) radiation, the radiation weighting factor is 1, and the tissue weighting factors add up to 1, and therefore, for example, an absorbed dose of 1 mGy equals an effective dose of 1 mSv.

'''[[#Top|Back to Top]]'''

==Dose Limits==
'''Dose limits help ensure that no person is exposed to an excessive amount of [[ICRPædia Guide to the Basics of Ionising Radiation|radiation]] in normal, planned situations.'''

They are the strongest form of restriction on dose to an individual. Exceeding a dose limit is contrary to regulations in most countries.

 
===Dose Limits Recommended by ICRP===
{| border="1" style="border-collapse: collapse; line-height: 1.4em; height: 450px;"

! style="width: 30%;" | Type of Dose Limit
! style="width: 30%;" | Limit on Dose from [[System_of_radiation_protection_module_2#Exposure Categories and Situations | Occupational Exposure]]
! style="width: 30%;" | Limit on Dose from [[System_of_radiation_protection_module_2#Exposure Categories and Situations | Public Exposure]]
|-
|[[System_of_radiation_protection_module_2#Effective Dose | Effective Dose]]
|20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv After a worker declares a pregnancy, the dose to the embryo/fetus should not exceed about 1 mSv during the remainder of the pregnancy 
|1 mSv in a year In special circumstances, a higher value could be allowed in a single year, provided that the average over 5 years does not exceed 1 mSv per year 
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Lens of the Eye
|20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv 
|15 mSv in a year
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Skin Averaged over 1 cm2 of skin regardless of the area exposed 
|500 mSv in a year
|50 mSv in a year
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Hands and Feet
|500 mSv in a year
| -
|}
{|span style="font-size:85%; line-height: 1.1em;"
|''Dose limits are primarily from [[ICRP Publication 103]] Table 6. The recommendation for pregnant workers is from [[ICRP Publication 103]] Paragraph 186. The occupational limit for the lens of the eye is from Paragraph 3 of the ICRP Statement on Tissue Reactions in [[ICRP Publication 118]].

''
|}

Dose limits alone are not enough to ensure adequate protection. They function in combination with the [[System_Of_Radiation_Protection_Overview#Fundamental Principles of Radiological Protection | fundamental principles]] of justification and optimisation.

These limits apply only to doses received above the normal local [[Sources of Radiation Exposure | natural background radiation]].

Limits on [[System_of_radiation_protection_module_2#Effective Dose | effective dose]], combined with optimisation of protection, are designed to avoid a risk of [[Effects of Exposure | stochastic effects]] that would be considered intolerable in a [[System_of_radiation_protection_module_2#Exposure Categories and Situations | planned exposure situation]].

Limits on [[System_of_radiation_protection_module_2#Equivalent Dose | equivalent dose to an organ]], combined with optimisation of protection, are designed to prevent the occurance of [[Effects of Exposure | deterministic effects]].

Dose limits apply only in [[System_of_radiation_protection_module_2#Exposure Categories and Situations | planned exposure situations]]. In other situations, restrictions on individual dose are called reference levels. They provide the additional flexibility needed in [[System_of_radiation_protection_module_2#Exposure Categories and Situations | emergency and existing exposure situations]] to make sure protection is optimised.

Dose limits do not apply to [[System_of_radiation_protection_module_2#Exposure Categories and Situations | medical exposures]]. If they did, the effectiveness of diagnosis or treatment might be reduced, doing more harm than good for the patient. The emphasis is on justification of medical procedures and optimisation of protection.

'''[[#Top|Back to Top]]'''

[[File:ICRPGuide.JPG|50px|link=Guide_to_the_System_of_Radiological_Protection]]Take me back to the ICRP's [[Guide_to_the_System_of_Radiological_Protection|Guide to the System of Radiological Protection]]!

System Of Radiation Protection Overview

2019-10-24T18:54:14Z

Karen Clement: /* Fundamental Principles of Radiological Protection */

System Of Radiation Protection Overview

2019-10-24T18:52:22Z

Karen Clement: /* What is the System of Radiological Protection? */

System of radiation protection module 2

2019-10-24T17:49:42Z

Karen Clement:

[[#top| ]]
__FORCETOC__
[[File:ICRPGuide.JPG|150px|thumb|right|link=Guide_to_the_System_of_Radiological_Protection|Take me back to the ICRP's [[Guide_to_the_System_of_Radiological_Protection|Guide to the System of Radiological Protection]]!]]

==Exposure Categories and Situations==
 
'''Categories of exposure and exposure situations are used to consider how best to approach radiological protection in different circumstances.'''

Exposure Categories are: occupational, public, and medical.

Exposure Situations are: planned, existing, and emergency.

Categories and Situations are considered together to help guide the best approach to radiological protection in a particular circumstance.

{| class="wikitable"
| style="height: 80px;" |
! [[Image: OccupationalE.png |40px|link=]]

[[Glossary#Occupational Exposure | Occupational Exposure]]

''Exposure of workers incurred as a result of their work''

! [[Image: PublicE.png|40px|link=]]

[[Glossary#Public Exposure | Public Exposure]]

''Exposure of members of the public other than occupational and medical exposures, and not including the normal local natural background radiation''

! [[Image: MedicalE.png |40px|link=]]

[[Glossary#Medical Exposure | Medical Exposure]]

''Exposure of patients as part of their diagnosis or treatment, volunteers helping in the support and comfort of patients, and volunteers in biomedical research
''

|-
! [[Image: PlannedES.png |40px|link=]]

[[Glossary#Planned Exposure Situation | Planned Exposure Situation]]

''Situations where radiological protection can be planned in advance, and exposures can be reasonably predicted''

| style="height: 80px;" | e.g. working in a hospital, uranium mine, or nuclear power plant
| e.g. visiting a hospital, living near a nuclear power plant
| e.g. getting an x-ray, CT scan, or radiation treatment
|-
! [[Image: ExistingES.png |40px|link=]]

[[Glossary#Existing Exposure Situation | Existing Exposure Situation]]

''Situations that already exist when a decision on control has to be taken''

| style="height: 80px;" | e.g. aircrew and astronauts exposed to [[Cosmic Radiation in Aviation | cosmic radiation]]
| e.g. [[Exposure to Radon at Home | radon gas in the home]]
| n/a
|-
! [[Image: EmergencyES.png |40px|link=]]

[[Glossary#Emergency Exposure Situation | Emergency Exposure Situation]]

''Unexpected situations that may require urgent protective actions''

| style="height: 80px;" | e.g. in the immediate response to an accident
| e.g. during a major accident
| n/a
|}

'''[[#Top|Back to Top]]'''

==Radiation Dose==

Radiation dose is a measure of the amount of exposure to radiation. There are three kinds of dose in radiological protection. ''Absorbed dose'' is a measureable, physical quantity, while ''equivalent dose'' and ''effective dose'' are specifically for radiological protection purposes.

''Effective dose'' in particular is a central feature of radiological protection. It sums up any number of different exposures into a single number that reflects, in a general way, the overall risk. The concept may be complex, but it makes radiological protection practical to implement.

===Absorbed Dose===
Absorbed dose is the amount of energy deposited by radiation in a mass.
The mass can be anything: water, rock, air, people, etc.
Absorbed dose is expressed in milligrays (mGy).

Absorbed dose is a measurable, physical quantity. It is expressed in grays (Gy), or, more frequently milligrays (mGy), which are 1/1000th of a gray. 1 gray = 1 joule of energy deposited in 1 kilogram of material i.e. 1 Gy = 1 J/kg

===Equivalent Dose===
Equivalent dose is calculated for individual organs.
It is based on the absorbed dose to an organ, adjusted to account for the effectiveness of the type of radiation.
Equivalent dose is expressed in millisieverts (mSv) to an organ.

Equivalent dose = absorbed Dose multiplied the appropriate radiation weighting factor. The radiation weighting factors are needed because different types of radiation (like alpha, beta, gamma, and neutrons) can have different effects even if the absorbed dose is the same. Equivalent dose is expressed in sieverts (Sv), or, more frequently, millisieverts (mSv) which are 1/1000th of a sievert, and the organ should always be specified (for example "25 mSv to the skin"). In the simplest cases, for gamma (photon) and beta (electron) radiation, the radiation weighting factor is 1, and therefore, for example, an absorbed dose of 1 mGy in an organ equals an equivalent dose of 1 mSv to that organ.

===Effective Dose===
Effective dose is calculated for the whole body. It is sometimes called whole-body dose.
It is the addition of equivalent doses to all organs, each adjusted to account for the sensitivity of the organ to radiation.
Effective dose is expressed in millisieverts (mSv).

Effective dose = sum for all organs of (equivalent dose to the organ times the appropriate tissue weighting factor)
The tissue weighting factors are needed because different organs have different levels of sensitivity to radiation, even if the equivalent dose is the same. Effective dose is expressed in sieverts (Sv), or, more frequently, millisieverts (mSv) which are 1/1000th of a sievert. This is the most frequently used dose in radiological protection. Unless you see mention of a specific organ, a "dose" in Sv or mSv is the effective dose. In the simplest cases, for uniform whole-body exposure to gamma (photon) or beta (electron) radiation, the radiation weighting factor is 1, and the tissue weighting factors add up to 1, and therefore, for example, an absorbed dose of 1 mGy equals an effective dose of 1 mSv.

'''[[#Top|Back to Top]]'''

==Dose Limits==
'''Dose limits help ensure that no person is exposed to an excessive amount of [[ICRPædia Guide to the Basics of Ionising Radiation|radiation]] in normal, planned situations.'''

They are the strongest form of restriction on dose to an individual. Exceeding a dose limit is contrary to regulations in most countries.

 
===Dose Limits Recommended by ICRP===
{| border="1" style="border-collapse: collapse; line-height: 1.4em; height: 450px;"

! style="width: 30%;" | Type of Dose Limit
! style="width: 30%;" | Limit on Dose from [[System_of_radiation_protection_module_2#Exposure Categories and Situations | Occupational Exposure]]
! style="width: 30%;" | Limit on Dose from [[System_of_radiation_protection_module_2#Exposure Categories and Situations | Public Exposure]]
|-
|[[System_of_radiation_protection_module_2#Effective Dose | Effective Dose]]
|20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv After a worker declares a pregnancy, the dose to the embryo/fetus should not exceed about 1 mSv during the remainder of the pregnancy 
|1 mSv in a year In special circumstances, a higher value could be allowed in a single year, provided that the average over 5 years does not exceed 1 mSv per year 
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Lens of the Eye
|20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv 
|15 mSv in a year
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Skin Averaged over 1 cm2 of skin regardless of the area exposed 
|500 mSv in a year
|50 mSv in a year
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Hands and Feet
|500 mSv in a year
| -
|}
{|span style="font-size:85%; line-height: 1.1em;"
|''Dose limits are primarily from [[ICRP Publication 103]] Table 6. The recommendation for pregnant workers is from [[ICRP Publication 103]] Paragraph 186. The occupational limit for the lens of the eye is from Paragraph 3 of the ICRP Statement on Tissue Reactions in [[ICRP Publication 118]].

''
|}

Dose limits alone are not enough to ensure adequate protection. They function in combination with the [[System_Of_Radiation_Protection_Overview#Fundamental Principles of Radiological Protection | fundamental principles]] of justification and optimisation.

These limits apply only to doses received above the normal local [[Sources of Radiation Exposure | natural background radiation]].

Limits on [[System_of_radiation_protection_module_2#Effective Dose | effective dose]], combined with optimisation of protection, are designed to avoid a risk of [[Effects of Exposure | stochastic effects]] that would be considered intolerable in a [[System_of_radiation_protection_module_2#Exposure Categories and Situations | planned exposure situation]].

Limits on [[System_of_radiation_protection_module_2#Equivalent Dose | equivalent dose to an organ]], combined with optimisation of protection, are designed to prevent the occurance of [[Effects of Exposure | deterministic effects]].

Dose limits apply only in [[System_of_radiation_protection_module_2#Exposure Categories and Situations | planned exposure situations]]. In other situations, restrictions on individual dose are called reference levels. They provide the additional flexibility needed in [[System_of_radiation_protection_module_2#Exposure Categories and Situations | emergency and existing exposure situations]] to make sure protection is optimised.

Dose limits do not apply to [[System_of_radiation_protection_module_2#Exposure Categories and Situations | medical exposures]]. If they did, the effectiveness of diagnosis or treatment might be reduced, doing more harm than good for the patient. The emphasis is on justification of medical procedures and optimisation of protection.

'''[[#Top|Back to Top]]'''

[[File:ICRPGuide.JPG|50px|link=Guide_to_the_System_of_Radiological_Protection]]Take me back to the ICRP's [[Guide_to_the_System_of_Radiological_Protection|Guide to the System of Radiological Protection]]!

System of radiation protection module 2

2019-10-24T16:00:51Z

Karen Clement: /* Dose Limits */

[[#top| ]]
__FORCETOC__
[[File:ICRPGuide.JPG|150px|thumb|right|link=Guide_to_the_System_of_Radiological_Protection|Take me back to the ICRP's [[Guide_to_the_System_of_Radiological_Protection|Guide to the System of Radiological Protection]]!]]

Introduction

==Exposure Categories and Situations==
 
'''Categories of exposure and exposure situations are used to consider how best to approach radiological protection in different circumstances.'''

Exposure Categories are: occupational, public, and medical.

Exposure Situations are: planned, existing, and emergency.

Categories and Situations are considered together to help guide the best approach to radiological protection in a particular circumstance.

{| class="wikitable"
| style="height: 80px;" |
! [[Image: OccupationalE.png |40px|link=]]

[[Glossary#Occupational Exposure | Occupational Exposure]]

''Exposure of workers incurred as a result of their work''

! [[Image: PublicE.png|40px|link=]]

[[Glossary#Public Exposure | Public Exposure]]

''Exposure of members of the public other than occupational and medical exposures, and not including the normal local natural background radiation''

! [[Image: MedicalE.png |40px|link=]]

[[Glossary#Medical Exposure | Medical Exposure]]

''Exposure of patients as part of their diagnosis or treatment, volunteers helping in the support and comfort of patients, and volunteers in biomedical research
''

|-
! [[Image: PlannedES.png |40px|link=]]

[[Glossary#Planned Exposure Situation | Planned Exposure Situation]]

''Situations where radiological protection can be planned in advance, and exposures can be reasonably predicted''

| style="height: 80px;" | e.g. working in a hospital, uranium mine, or nuclear power plant
| e.g. visiting a hospital, living near a nuclear power plant
| e.g. getting an x-ray, CT scan, or radiation treatment
|-
! [[Image: ExistingES.png |40px|link=]]

[[Glossary#Existing Exposure Situation | Existing Exposure Situation]]

''Situations that already exist when a decision on control has to be taken''

| style="height: 80px;" | e.g. aircrew and astronauts exposed to [[Cosmic Radiation in Aviation | cosmic radiation]]
| e.g. [[Exposure to Radon at Home | radon gas in the home]]
| n/a
|-
! [[Image: EmergencyES.png |40px|link=]]

[[Glossary#Emergency Exposure Situation | Emergency Exposure Situation]]

''Unexpected situations that may require urgent protective actions''

| style="height: 80px;" | e.g. in the immediate response to an accident
| e.g. during a major accident
| n/a
|}

'''[[#Top|Back to Top]]'''

==Radiation Dose==

Radiation dose is a measure of the amount of exposure to radiation. There are three kinds of dose in radiological protection. ''Absorbed dose'' is a measureable, physical quantity, while ''equivalent dose'' and ''effective dose'' are specifically for radiological protection purposes.

''Effective dose'' in particular is a central feature of radiological protection. It sums up any number of different exposures into a single number that reflects, in a general way, the overall risk. The concept may be complex, but it makes radiological protection practical to implement.

===Absorbed Dose===
Absorbed dose is the amount of energy deposited by radiation in a mass.
The mass can be anything: water, rock, air, people, etc.
Absorbed dose is expressed in milligrays (mGy).

Absorbed dose is a measurable, physical quantity. It is expressed in grays (Gy), or, more frequently milligrays (mGy), which are 1/1000th of a gray. 1 gray = 1 joule of energy deposited in 1 kilogram of material i.e. 1 Gy = 1 J/kg

===Equivalent Dose===
Equivalent dose is calculated for individual organs.
It is based on the absorbed dose to an organ, adjusted to account for the effectiveness of the type of radiation.
Equivalent dose is expressed in millisieverts (mSv) to an organ.

Equivalent dose = absorbed Dose multiplied the appropriate radiation weighting factor. The radiation weighting factors are needed because different types of radiation (like alpha, beta, gamma, and neutrons) can have different effects even if the absorbed dose is the same. Equivalent dose is expressed in sieverts (Sv), or, more frequently, millisieverts (mSv) which are 1/1000th of a sievert, and the organ should always be specified (for example "25 mSv to the skin"). In the simplest cases, for gamma (photon) and beta (electron) radiation, the radiation weighting factor is 1, and therefore, for example, an absorbed dose of 1 mGy in an organ equals an equivalent dose of 1 mSv to that organ.

===Effective Dose===
Effective dose is calculated for the whole body. It is sometimes called whole-body dose.
It is the addition of equivalent doses to all organs, each adjusted to account for the sensitivity of the organ to radiation.
Effective dose is expressed in millisieverts (mSv).

Effective dose = sum for all organs of (equivalent dose to the organ times the appropriate tissue weighting factor)
The tissue weighting factors are needed because different organs have different levels of sensitivity to radiation, even if the equivalent dose is the same. Effective dose is expressed in sieverts (Sv), or, more frequently, millisieverts (mSv) which are 1/1000th of a sievert. This is the most frequently used dose in radiological protection. Unless you see mention of a specific organ, a "dose" in Sv or mSv is the effective dose. In the simplest cases, for uniform whole-body exposure to gamma (photon) or beta (electron) radiation, the radiation weighting factor is 1, and the tissue weighting factors add up to 1, and therefore, for example, an absorbed dose of 1 mGy equals an effective dose of 1 mSv.

'''[[#Top|Back to Top]]'''

==Dose Limits==
'''Dose limits help ensure that no person is exposed to an excessive amount of [[ICRPædia Guide to the Basics of Ionising Radiation|radiation]] in normal, planned situations.'''

They are the strongest form of restriction on dose to an individual. Exceeding a dose limit is contrary to regulations in most countries.

 
===Dose Limits Recommended by ICRP===
{| border="1" style="border-collapse: collapse; line-height: 1.4em; height: 450px;"

! style="width: 30%;" | Type of Dose Limit
! style="width: 30%;" | Limit on Dose from [[System_of_radiation_protection_module_2#Exposure Categories and Situations | Occupational Exposure]]
! style="width: 30%;" | Limit on Dose from [[System_of_radiation_protection_module_2#Exposure Categories and Situations | Public Exposure]]
|-
|[[System_of_radiation_protection_module_2#Effective Dose | Effective Dose]]
|20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv After a worker declares a pregnancy, the dose to the embryo/fetus should not exceed about 1 mSv during the remainder of the pregnancy 
|1 mSv in a year In special circumstances, a higher value could be allowed in a single year, provided that the average over 5 years does not exceed 1 mSv per year 
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Lens of the Eye
|20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv 
|15 mSv in a year
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Skin Averaged over 1 cm2 of skin regardless of the area exposed 
|500 mSv in a year
|50 mSv in a year
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Hands and Feet
|500 mSv in a year
| -
|}
{|span style="font-size:85%; line-height: 1.1em;"
|''Dose limits are primarily from [[ICRP Publication 103]] Table 6. The recommendation for pregnant workers is from [[ICRP Publication 103]] Paragraph 186. The occupational limit for the lens of the eye is from Paragraph 3 of the ICRP Statement on Tissue Reactions in [[ICRP Publication 118]].

''
|}

Dose limits alone are not enough to ensure adequate protection. They function in combination with the [[System_Of_Radiation_Protection_Overview#Fundamental Principles of Radiological Protection | fundamental principles]] of justification and optimisation.

These limits apply only to doses received above the normal local [[Sources of Radiation Exposure | natural background radiation]].

Limits on [[System_of_radiation_protection_module_2#Effective Dose | effective dose]], combined with optimisation of protection, are designed to avoid a risk of [[Effects of Exposure | stochastic effects]] that would be considered intolerable in a [[System_of_radiation_protection_module_2#Exposure Categories and Situations | planned exposure situation]].

Limits on [[System_of_radiation_protection_module_2#Equivalent Dose | equivalent dose to an organ]], combined with optimisation of protection, are designed to prevent the occurance of [[Effects of Exposure | deterministic effects]].

Dose limits apply only in [[System_of_radiation_protection_module_2#Exposure Categories and Situations | planned exposure situations]]. In other situations, restrictions on individual dose are called reference levels. They provide the additional flexibility needed in [[System_of_radiation_protection_module_2#Exposure Categories and Situations | emergency and existing exposure situations]] to make sure protection is optimised.

Dose limits do not apply to [[System_of_radiation_protection_module_2#Exposure Categories and Situations | medical exposures]]. If they did, the effectiveness of diagnosis or treatment might be reduced, doing more harm than good for the patient. The emphasis is on justification of medical procedures and optimisation of protection.

'''[[#Top|Back to Top]]'''

[[File:ICRPGuide.JPG|50px|link=Guide_to_the_System_of_Radiological_Protection]]Take me back to the ICRP's [[Guide_to_the_System_of_Radiological_Protection|Guide to the System of Radiological Protection]]!

System Of Radiation Protection Overview

2019-10-24T15:57:23Z

Karen Clement:

System Of Radiation Protection Overview

2019-10-24T15:56:28Z

Karen Clement: /* For People */

System Of Radiation Protection Overview

2019-10-24T15:56:19Z

Karen Clement: /* Objectives of Radiological Protection */

System of radiation protection module 2

2019-10-24T15:54:51Z

Karen Clement: /* Exposure Categories and Situations */

[[#top| ]]
__FORCETOC__
[[File:ICRPGuide.JPG|150px|thumb|right|link=Guide_to_the_System_of_Radiological_Protection|Take me back to the ICRP's [[Guide_to_the_System_of_Radiological_Protection|Guide to the System of Radiological Protection]]!]]

Introduction

==Exposure Categories and Situations==
 
'''Categories of exposure and exposure situations are used to consider how best to approach radiological protection in different circumstances.'''

Exposure Categories are: occupational, public, and medical.

Exposure Situations are: planned, existing, and emergency.

Categories and Situations are considered together to help guide the best approach to radiological protection in a particular circumstance.

{| class="wikitable"
| style="height: 80px;" |
! [[Image: OccupationalE.png |40px|link=]]

[[Glossary#Occupational Exposure | Occupational Exposure]]

''Exposure of workers incurred as a result of their work''

! [[Image: PublicE.png|40px|link=]]

[[Glossary#Public Exposure | Public Exposure]]

''Exposure of members of the public other than occupational and medical exposures, and not including the normal local natural background radiation''

! [[Image: MedicalE.png |40px|link=]]

[[Glossary#Medical Exposure | Medical Exposure]]

''Exposure of patients as part of their diagnosis or treatment, volunteers helping in the support and comfort of patients, and volunteers in biomedical research
''

|-
! [[Image: PlannedES.png |40px|link=]]

[[Glossary#Planned Exposure Situation | Planned Exposure Situation]]

''Situations where radiological protection can be planned in advance, and exposures can be reasonably predicted''

| style="height: 80px;" | e.g. working in a hospital, uranium mine, or nuclear power plant
| e.g. visiting a hospital, living near a nuclear power plant
| e.g. getting an x-ray, CT scan, or radiation treatment
|-
! [[Image: ExistingES.png |40px|link=]]

[[Glossary#Existing Exposure Situation | Existing Exposure Situation]]

''Situations that already exist when a decision on control has to be taken''

| style="height: 80px;" | e.g. aircrew and astronauts exposed to [[Cosmic Radiation in Aviation | cosmic radiation]]
| e.g. [[Exposure to Radon at Home | radon gas in the home]]
| n/a
|-
! [[Image: EmergencyES.png |40px|link=]]

[[Glossary#Emergency Exposure Situation | Emergency Exposure Situation]]

''Unexpected situations that may require urgent protective actions''

| style="height: 80px;" | e.g. in the immediate response to an accident
| e.g. during a major accident
| n/a
|}

'''[[#Top|Back to Top]]'''

==Radiation Dose==

Radiation dose is a measure of the amount of exposure to radiation. There are three kinds of dose in radiological protection. ''Absorbed dose'' is a measureable, physical quantity, while ''equivalent dose'' and ''effective dose'' are specifically for radiological protection purposes.

''Effective dose'' in particular is a central feature of radiological protection. It sums up any number of different exposures into a single number that reflects, in a general way, the overall risk. The concept may be complex, but it makes radiological protection practical to implement.

===Absorbed Dose===
Absorbed dose is the amount of energy deposited by radiation in a mass.
The mass can be anything: water, rock, air, people, etc.
Absorbed dose is expressed in milligrays (mGy).

Absorbed dose is a measurable, physical quantity. It is expressed in grays (Gy), or, more frequently milligrays (mGy), which are 1/1000th of a gray. 1 gray = 1 joule of energy deposited in 1 kilogram of material i.e. 1 Gy = 1 J/kg

===Equivalent Dose===
Equivalent dose is calculated for individual organs.
It is based on the absorbed dose to an organ, adjusted to account for the effectiveness of the type of radiation.
Equivalent dose is expressed in millisieverts (mSv) to an organ.

Equivalent dose = absorbed Dose multiplied the appropriate radiation weighting factor. The radiation weighting factors are needed because different types of radiation (like alpha, beta, gamma, and neutrons) can have different effects even if the absorbed dose is the same. Equivalent dose is expressed in sieverts (Sv), or, more frequently, millisieverts (mSv) which are 1/1000th of a sievert, and the organ should always be specified (for example "25 mSv to the skin"). In the simplest cases, for gamma (photon) and beta (electron) radiation, the radiation weighting factor is 1, and therefore, for example, an absorbed dose of 1 mGy in an organ equals an equivalent dose of 1 mSv to that organ.

===Effective Dose===
Effective dose is calculated for the whole body. It is sometimes called whole-body dose.
It is the addition of equivalent doses to all organs, each adjusted to account for the sensitivity of the organ to radiation.
Effective dose is expressed in millisieverts (mSv).

Effective dose = sum for all organs of (equivalent dose to the organ times the appropriate tissue weighting factor)
The tissue weighting factors are needed because different organs have different levels of sensitivity to radiation, even if the equivalent dose is the same. Effective dose is expressed in sieverts (Sv), or, more frequently, millisieverts (mSv) which are 1/1000th of a sievert. This is the most frequently used dose in radiological protection. Unless you see mention of a specific organ, a "dose" in Sv or mSv is the effective dose. In the simplest cases, for uniform whole-body exposure to gamma (photon) or beta (electron) radiation, the radiation weighting factor is 1, and the tissue weighting factors add up to 1, and therefore, for example, an absorbed dose of 1 mGy equals an effective dose of 1 mSv.

'''[[#Top|Back to Top]]'''

==Dose Limits==
'''Dose limits help ensure that no person is exposed to an excessive amount of [[ICRPædia Guide to the Basics of Ionising Radiation|radiation]] in normal, planned situations.'''

They are the strongest form of restriction on dose to an individual. Exceeding a dose limit is contrary to regulations in most countries.

 

{| border="1" style="border-collapse: collapse; line-height: 1.4em; height: 450px;"
|+<center> '''Dose Limits Recommended by ICRP''' </center>
! style="width: 30%;" | Type of Dose Limit
! style="width: 30%;" | Limit on Dose from [[System_of_radiation_protection_module_2#Exposure Categories and Situations | Occupational Exposure]]
! style="width: 30%;" | Limit on Dose from [[System_of_radiation_protection_module_2#Exposure Categories and Situations | Public Exposure]]
|-
|[[System_of_radiation_protection_module_2#Effective Dose | Effective Dose]]
|20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv After a worker declares a pregnancy, the dose to the embryo/fetus should not exceed about 1 mSv during the remainder of the pregnancy 
|1 mSv in a year In special circumstances, a higher value could be allowed in a single year, provided that the average over 5 years does not exceed 1 mSv per year 
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Lens of the Eye
|20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv 
|15 mSv in a year
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Skin Averaged over 1 cm2 of skin regardless of the area exposed 
|500 mSv in a year
|50 mSv in a year
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Hands and Feet
|500 mSv in a year
| -
|}
{|span style="font-size:85%; line-height: 1.1em;"
|''Dose limits are primarily from [[ICRP Publication 103]] Table 6. The recommendation for pregnant workers is from [[ICRP Publication 103]] Paragraph 186. The occupational limit for the lens of the eye is from Paragraph 3 of the ICRP Statement on Tissue Reactions in [[ICRP Publication 118]].

''
|}

Dose limits alone are not enough to ensure adequate protection. They function in combination with the [[System_Of_Radiation_Protection_Overview#Fundamental Principles of Radiological Protection | fundamental principles]] of justification and optimisation.

These limits apply only to doses received above the normal local [[Sources of Radiation Exposure | natural background radiation]].

Limits on [[System_of_radiation_protection_module_2#Effective Dose | effective dose]], combined with optimisation of protection, are designed to avoid a risk of [[Effects of Exposure | stochastic effects]] that would be considered intolerable in a [[System_of_radiation_protection_module_2#Exposure Categories and Situations | planned exposure situation]].

Limits on [[System_of_radiation_protection_module_2#Equivalent Dose | equivalent dose to an organ]], combined with optimisation of protection, are designed to prevent the occurance of [[Effects of Exposure | deterministic effects]].

Dose limits apply only in [[System_of_radiation_protection_module_2#Exposure Categories and Situations | planned exposure situations]]. In other situations, restrictions on individual dose are called reference levels. They provide the additional flexibility needed in [[System_of_radiation_protection_module_2#Exposure Categories and Situations | emergency and existing exposure situations]] to make sure protection is optimised.

Dose limits do not apply to [[System_of_radiation_protection_module_2#Exposure Categories and Situations | medical exposures]]. If they did, the effectiveness of diagnosis or treatment might be reduced, doing more harm than good for the patient. The emphasis is on justification of medical procedures and optimisation of protection.

'''[[#Top|Back to Top]]'''

[[File:ICRPGuide.JPG|50px|link=Guide_to_the_System_of_Radiological_Protection]]Take me back to the ICRP's [[Guide_to_the_System_of_Radiological_Protection|Guide to the System of Radiological Protection]]!

System of radiation protection module 2

2019-10-24T15:54:35Z

Karen Clement: /* Effective Dose */

[[#top| ]]
__FORCETOC__
[[File:ICRPGuide.JPG|150px|thumb|right|link=Guide_to_the_System_of_Radiological_Protection|Take me back to the ICRP's [[Guide_to_the_System_of_Radiological_Protection|Guide to the System of Radiological Protection]]!]]

Introduction

==Exposure Categories and Situations==
 
'''Categories of exposure and exposure situations are used to consider how best to approach radiological protection in different circumstances.'''

Exposure Categories are: occupational, public, and medical.

Exposure Situations are: planned, existing, and emergency.

Categories and Situations are considered together to help guide the best approach to radiological protection in a particular circumstance.

{| class="wikitable"
| style="height: 80px;" |
! [[Image: OccupationalE.png |40px|link=]]

[[Glossary#Occupational Exposure | Occupational Exposure]]

''Exposure of workers incurred as a result of their work''

! [[Image: PublicE.png|40px|link=]]

[[Glossary#Public Exposure | Public Exposure]]

''Exposure of members of the public other than occupational and medical exposures, and not including the normal local natural background radiation''

! [[Image: MedicalE.png |40px|link=]]

[[Glossary#Medical Exposure | Medical Exposure]]

''Exposure of patients as part of their diagnosis or treatment, volunteers helping in the support and comfort of patients, and volunteers in biomedical research
''

|-
! [[Image: PlannedES.png |40px|link=]]

[[Glossary#Planned Exposure Situation | Planned Exposure Situation]]

''Situations where radiological protection can be planned in advance, and exposures can be reasonably predicted''

| style="height: 80px;" | e.g. working in a hospital, uranium mine, or nuclear power plant
| e.g. visiting a hospital, living near a nuclear power plant
| e.g. getting an x-ray, CT scan, or radiation treatment
|-
! [[Image: ExistingES.png |40px|link=]]

[[Glossary#Existing Exposure Situation | Existing Exposure Situation]]

''Situations that already exist when a decision on control has to be taken''

| style="height: 80px;" | e.g. aircrew and astronauts exposed to [[Cosmic Radiation in Aviation | cosmic radiation]]
| e.g. [[Exposure to Radon at Home | radon gas in the home]]
| n/a
|-
! [[Image: EmergencyES.png |40px|link=]]

[[Glossary#Emergency Exposure Situation | Emergency Exposure Situation]]

''Unexpected situations that may require urgent protective actions''

| style="height: 80px;" | e.g. in the immediate response to an accident
| e.g. during a major accident
| n/a
|}

==Radiation Dose==

Radiation dose is a measure of the amount of exposure to radiation. There are three kinds of dose in radiological protection. ''Absorbed dose'' is a measureable, physical quantity, while ''equivalent dose'' and ''effective dose'' are specifically for radiological protection purposes.

''Effective dose'' in particular is a central feature of radiological protection. It sums up any number of different exposures into a single number that reflects, in a general way, the overall risk. The concept may be complex, but it makes radiological protection practical to implement.

===Absorbed Dose===
Absorbed dose is the amount of energy deposited by radiation in a mass.
The mass can be anything: water, rock, air, people, etc.
Absorbed dose is expressed in milligrays (mGy).

Absorbed dose is a measurable, physical quantity. It is expressed in grays (Gy), or, more frequently milligrays (mGy), which are 1/1000th of a gray. 1 gray = 1 joule of energy deposited in 1 kilogram of material i.e. 1 Gy = 1 J/kg

===Equivalent Dose===
Equivalent dose is calculated for individual organs.
It is based on the absorbed dose to an organ, adjusted to account for the effectiveness of the type of radiation.
Equivalent dose is expressed in millisieverts (mSv) to an organ.

Equivalent dose = absorbed Dose multiplied the appropriate radiation weighting factor. The radiation weighting factors are needed because different types of radiation (like alpha, beta, gamma, and neutrons) can have different effects even if the absorbed dose is the same. Equivalent dose is expressed in sieverts (Sv), or, more frequently, millisieverts (mSv) which are 1/1000th of a sievert, and the organ should always be specified (for example "25 mSv to the skin"). In the simplest cases, for gamma (photon) and beta (electron) radiation, the radiation weighting factor is 1, and therefore, for example, an absorbed dose of 1 mGy in an organ equals an equivalent dose of 1 mSv to that organ.

===Effective Dose===
Effective dose is calculated for the whole body. It is sometimes called whole-body dose.
It is the addition of equivalent doses to all organs, each adjusted to account for the sensitivity of the organ to radiation.
Effective dose is expressed in millisieverts (mSv).

Effective dose = sum for all organs of (equivalent dose to the organ times the appropriate tissue weighting factor)
The tissue weighting factors are needed because different organs have different levels of sensitivity to radiation, even if the equivalent dose is the same. Effective dose is expressed in sieverts (Sv), or, more frequently, millisieverts (mSv) which are 1/1000th of a sievert. This is the most frequently used dose in radiological protection. Unless you see mention of a specific organ, a "dose" in Sv or mSv is the effective dose. In the simplest cases, for uniform whole-body exposure to gamma (photon) or beta (electron) radiation, the radiation weighting factor is 1, and the tissue weighting factors add up to 1, and therefore, for example, an absorbed dose of 1 mGy equals an effective dose of 1 mSv.

'''[[#Top|Back to Top]]'''

==Dose Limits==
'''Dose limits help ensure that no person is exposed to an excessive amount of [[ICRPædia Guide to the Basics of Ionising Radiation|radiation]] in normal, planned situations.'''

They are the strongest form of restriction on dose to an individual. Exceeding a dose limit is contrary to regulations in most countries.

 

{| border="1" style="border-collapse: collapse; line-height: 1.4em; height: 450px;"
|+<center> '''Dose Limits Recommended by ICRP''' </center>
! style="width: 30%;" | Type of Dose Limit
! style="width: 30%;" | Limit on Dose from [[System_of_radiation_protection_module_2#Exposure Categories and Situations | Occupational Exposure]]
! style="width: 30%;" | Limit on Dose from [[System_of_radiation_protection_module_2#Exposure Categories and Situations | Public Exposure]]
|-
|[[System_of_radiation_protection_module_2#Effective Dose | Effective Dose]]
|20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv After a worker declares a pregnancy, the dose to the embryo/fetus should not exceed about 1 mSv during the remainder of the pregnancy 
|1 mSv in a year In special circumstances, a higher value could be allowed in a single year, provided that the average over 5 years does not exceed 1 mSv per year 
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Lens of the Eye
|20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv 
|15 mSv in a year
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Skin Averaged over 1 cm2 of skin regardless of the area exposed 
|500 mSv in a year
|50 mSv in a year
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Hands and Feet
|500 mSv in a year
| -
|}
{|span style="font-size:85%; line-height: 1.1em;"
|''Dose limits are primarily from [[ICRP Publication 103]] Table 6. The recommendation for pregnant workers is from [[ICRP Publication 103]] Paragraph 186. The occupational limit for the lens of the eye is from Paragraph 3 of the ICRP Statement on Tissue Reactions in [[ICRP Publication 118]].

''
|}

Dose limits alone are not enough to ensure adequate protection. They function in combination with the [[System_Of_Radiation_Protection_Overview#Fundamental Principles of Radiological Protection | fundamental principles]] of justification and optimisation.

These limits apply only to doses received above the normal local [[Sources of Radiation Exposure | natural background radiation]].

Limits on [[System_of_radiation_protection_module_2#Effective Dose | effective dose]], combined with optimisation of protection, are designed to avoid a risk of [[Effects of Exposure | stochastic effects]] that would be considered intolerable in a [[System_of_radiation_protection_module_2#Exposure Categories and Situations | planned exposure situation]].

Limits on [[System_of_radiation_protection_module_2#Equivalent Dose | equivalent dose to an organ]], combined with optimisation of protection, are designed to prevent the occurance of [[Effects of Exposure | deterministic effects]].

Dose limits apply only in [[System_of_radiation_protection_module_2#Exposure Categories and Situations | planned exposure situations]]. In other situations, restrictions on individual dose are called reference levels. They provide the additional flexibility needed in [[System_of_radiation_protection_module_2#Exposure Categories and Situations | emergency and existing exposure situations]] to make sure protection is optimised.

Dose limits do not apply to [[System_of_radiation_protection_module_2#Exposure Categories and Situations | medical exposures]]. If they did, the effectiveness of diagnosis or treatment might be reduced, doing more harm than good for the patient. The emphasis is on justification of medical procedures and optimisation of protection.

'''[[#Top|Back to Top]]'''

[[File:ICRPGuide.JPG|50px|link=Guide_to_the_System_of_Radiological_Protection]]Take me back to the ICRP's [[Guide_to_the_System_of_Radiological_Protection|Guide to the System of Radiological Protection]]!

System of radiation protection module 2

2019-10-24T15:54:21Z

Karen Clement: /* Dose Limits */

[[#top| ]]
__FORCETOC__
[[File:ICRPGuide.JPG|150px|thumb|right|link=Guide_to_the_System_of_Radiological_Protection|Take me back to the ICRP's [[Guide_to_the_System_of_Radiological_Protection|Guide to the System of Radiological Protection]]!]]

Introduction

==Exposure Categories and Situations==
 
'''Categories of exposure and exposure situations are used to consider how best to approach radiological protection in different circumstances.'''

Exposure Categories are: occupational, public, and medical.

Exposure Situations are: planned, existing, and emergency.

Categories and Situations are considered together to help guide the best approach to radiological protection in a particular circumstance.

{| class="wikitable"
| style="height: 80px;" |
! [[Image: OccupationalE.png |40px|link=]]

[[Glossary#Occupational Exposure | Occupational Exposure]]

''Exposure of workers incurred as a result of their work''

! [[Image: PublicE.png|40px|link=]]

[[Glossary#Public Exposure | Public Exposure]]

''Exposure of members of the public other than occupational and medical exposures, and not including the normal local natural background radiation''

! [[Image: MedicalE.png |40px|link=]]

[[Glossary#Medical Exposure | Medical Exposure]]

''Exposure of patients as part of their diagnosis or treatment, volunteers helping in the support and comfort of patients, and volunteers in biomedical research
''

|-
! [[Image: PlannedES.png |40px|link=]]

[[Glossary#Planned Exposure Situation | Planned Exposure Situation]]

''Situations where radiological protection can be planned in advance, and exposures can be reasonably predicted''

| style="height: 80px;" | e.g. working in a hospital, uranium mine, or nuclear power plant
| e.g. visiting a hospital, living near a nuclear power plant
| e.g. getting an x-ray, CT scan, or radiation treatment
|-
! [[Image: ExistingES.png |40px|link=]]

[[Glossary#Existing Exposure Situation | Existing Exposure Situation]]

''Situations that already exist when a decision on control has to be taken''

| style="height: 80px;" | e.g. aircrew and astronauts exposed to [[Cosmic Radiation in Aviation | cosmic radiation]]
| e.g. [[Exposure to Radon at Home | radon gas in the home]]
| n/a
|-
! [[Image: EmergencyES.png |40px|link=]]

[[Glossary#Emergency Exposure Situation | Emergency Exposure Situation]]

''Unexpected situations that may require urgent protective actions''

| style="height: 80px;" | e.g. in the immediate response to an accident
| e.g. during a major accident
| n/a
|}

==Radiation Dose==

Radiation dose is a measure of the amount of exposure to radiation. There are three kinds of dose in radiological protection. ''Absorbed dose'' is a measureable, physical quantity, while ''equivalent dose'' and ''effective dose'' are specifically for radiological protection purposes.

''Effective dose'' in particular is a central feature of radiological protection. It sums up any number of different exposures into a single number that reflects, in a general way, the overall risk. The concept may be complex, but it makes radiological protection practical to implement.

===Absorbed Dose===
Absorbed dose is the amount of energy deposited by radiation in a mass.
The mass can be anything: water, rock, air, people, etc.
Absorbed dose is expressed in milligrays (mGy).

Absorbed dose is a measurable, physical quantity. It is expressed in grays (Gy), or, more frequently milligrays (mGy), which are 1/1000th of a gray. 1 gray = 1 joule of energy deposited in 1 kilogram of material i.e. 1 Gy = 1 J/kg

===Equivalent Dose===
Equivalent dose is calculated for individual organs.
It is based on the absorbed dose to an organ, adjusted to account for the effectiveness of the type of radiation.
Equivalent dose is expressed in millisieverts (mSv) to an organ.

Equivalent dose = absorbed Dose multiplied the appropriate radiation weighting factor. The radiation weighting factors are needed because different types of radiation (like alpha, beta, gamma, and neutrons) can have different effects even if the absorbed dose is the same. Equivalent dose is expressed in sieverts (Sv), or, more frequently, millisieverts (mSv) which are 1/1000th of a sievert, and the organ should always be specified (for example "25 mSv to the skin"). In the simplest cases, for gamma (photon) and beta (electron) radiation, the radiation weighting factor is 1, and therefore, for example, an absorbed dose of 1 mGy in an organ equals an equivalent dose of 1 mSv to that organ.

===Effective Dose===
Effective dose is calculated for the whole body. It is sometimes called whole-body dose.
It is the addition of equivalent doses to all organs, each adjusted to account for the sensitivity of the organ to radiation.
Effective dose is expressed in millisieverts (mSv).

Effective dose = sum for all organs of (equivalent dose to the organ times the appropriate tissue weighting factor)
The tissue weighting factors are needed because different organs have different levels of sensitivity to radiation, even if the equivalent dose is the same. Effective dose is expressed in sieverts (Sv), or, more frequently, millisieverts (mSv) which are 1/1000th of a sievert. This is the most frequently used dose in radiological protection. Unless you see mention of a specific organ, a "dose" in Sv or mSv is the effective dose. In the simplest cases, for uniform whole-body exposure to gamma (photon) or beta (electron) radiation, the radiation weighting factor is 1, and the tissue weighting factors add up to 1, and therefore, for example, an absorbed dose of 1 mGy equals an effective dose of 1 mSv.

==Dose Limits==
'''Dose limits help ensure that no person is exposed to an excessive amount of [[ICRPædia Guide to the Basics of Ionising Radiation|radiation]] in normal, planned situations.'''

They are the strongest form of restriction on dose to an individual. Exceeding a dose limit is contrary to regulations in most countries.

 

{| border="1" style="border-collapse: collapse; line-height: 1.4em; height: 450px;"
|+<center> '''Dose Limits Recommended by ICRP''' </center>
! style="width: 30%;" | Type of Dose Limit
! style="width: 30%;" | Limit on Dose from [[System_of_radiation_protection_module_2#Exposure Categories and Situations | Occupational Exposure]]
! style="width: 30%;" | Limit on Dose from [[System_of_radiation_protection_module_2#Exposure Categories and Situations | Public Exposure]]
|-
|[[System_of_radiation_protection_module_2#Effective Dose | Effective Dose]]
|20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv After a worker declares a pregnancy, the dose to the embryo/fetus should not exceed about 1 mSv during the remainder of the pregnancy 
|1 mSv in a year In special circumstances, a higher value could be allowed in a single year, provided that the average over 5 years does not exceed 1 mSv per year 
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Lens of the Eye
|20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv 
|15 mSv in a year
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Skin Averaged over 1 cm2 of skin regardless of the area exposed 
|500 mSv in a year
|50 mSv in a year
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Hands and Feet
|500 mSv in a year
| -
|}
{|span style="font-size:85%; line-height: 1.1em;"
|''Dose limits are primarily from [[ICRP Publication 103]] Table 6. The recommendation for pregnant workers is from [[ICRP Publication 103]] Paragraph 186. The occupational limit for the lens of the eye is from Paragraph 3 of the ICRP Statement on Tissue Reactions in [[ICRP Publication 118]].

''
|}

Dose limits alone are not enough to ensure adequate protection. They function in combination with the [[System_Of_Radiation_Protection_Overview#Fundamental Principles of Radiological Protection | fundamental principles]] of justification and optimisation.

These limits apply only to doses received above the normal local [[Sources of Radiation Exposure | natural background radiation]].

Limits on [[System_of_radiation_protection_module_2#Effective Dose | effective dose]], combined with optimisation of protection, are designed to avoid a risk of [[Effects of Exposure | stochastic effects]] that would be considered intolerable in a [[System_of_radiation_protection_module_2#Exposure Categories and Situations | planned exposure situation]].

Limits on [[System_of_radiation_protection_module_2#Equivalent Dose | equivalent dose to an organ]], combined with optimisation of protection, are designed to prevent the occurance of [[Effects of Exposure | deterministic effects]].

Dose limits apply only in [[System_of_radiation_protection_module_2#Exposure Categories and Situations | planned exposure situations]]. In other situations, restrictions on individual dose are called reference levels. They provide the additional flexibility needed in [[System_of_radiation_protection_module_2#Exposure Categories and Situations | emergency and existing exposure situations]] to make sure protection is optimised.

Dose limits do not apply to [[System_of_radiation_protection_module_2#Exposure Categories and Situations | medical exposures]]. If they did, the effectiveness of diagnosis or treatment might be reduced, doing more harm than good for the patient. The emphasis is on justification of medical procedures and optimisation of protection.

'''[[#Top|Back to Top]]'''

[[File:ICRPGuide.JPG|50px|link=Guide_to_the_System_of_Radiological_Protection]]Take me back to the ICRP's [[Guide_to_the_System_of_Radiological_Protection|Guide to the System of Radiological Protection]]!

System of radiation protection module 2

2019-10-24T15:53:18Z

Karen Clement:

[[#top| ]]
__FORCETOC__
[[File:ICRPGuide.JPG|150px|thumb|right|link=Guide_to_the_System_of_Radiological_Protection|Take me back to the ICRP's [[Guide_to_the_System_of_Radiological_Protection|Guide to the System of Radiological Protection]]!]]

Introduction

==Exposure Categories and Situations==
 
'''Categories of exposure and exposure situations are used to consider how best to approach radiological protection in different circumstances.'''

Exposure Categories are: occupational, public, and medical.

Exposure Situations are: planned, existing, and emergency.

Categories and Situations are considered together to help guide the best approach to radiological protection in a particular circumstance.

{| class="wikitable"
| style="height: 80px;" |
! [[Image: OccupationalE.png |40px|link=]]

[[Glossary#Occupational Exposure | Occupational Exposure]]

''Exposure of workers incurred as a result of their work''

! [[Image: PublicE.png|40px|link=]]

[[Glossary#Public Exposure | Public Exposure]]

''Exposure of members of the public other than occupational and medical exposures, and not including the normal local natural background radiation''

! [[Image: MedicalE.png |40px|link=]]

[[Glossary#Medical Exposure | Medical Exposure]]

''Exposure of patients as part of their diagnosis or treatment, volunteers helping in the support and comfort of patients, and volunteers in biomedical research
''

|-
! [[Image: PlannedES.png |40px|link=]]

[[Glossary#Planned Exposure Situation | Planned Exposure Situation]]

''Situations where radiological protection can be planned in advance, and exposures can be reasonably predicted''

| style="height: 80px;" | e.g. working in a hospital, uranium mine, or nuclear power plant
| e.g. visiting a hospital, living near a nuclear power plant
| e.g. getting an x-ray, CT scan, or radiation treatment
|-
! [[Image: ExistingES.png |40px|link=]]

[[Glossary#Existing Exposure Situation | Existing Exposure Situation]]

''Situations that already exist when a decision on control has to be taken''

| style="height: 80px;" | e.g. aircrew and astronauts exposed to [[Cosmic Radiation in Aviation | cosmic radiation]]
| e.g. [[Exposure to Radon at Home | radon gas in the home]]
| n/a
|-
! [[Image: EmergencyES.png |40px|link=]]

[[Glossary#Emergency Exposure Situation | Emergency Exposure Situation]]

''Unexpected situations that may require urgent protective actions''

| style="height: 80px;" | e.g. in the immediate response to an accident
| e.g. during a major accident
| n/a
|}

==Radiation Dose==

Radiation dose is a measure of the amount of exposure to radiation. There are three kinds of dose in radiological protection. ''Absorbed dose'' is a measureable, physical quantity, while ''equivalent dose'' and ''effective dose'' are specifically for radiological protection purposes.

''Effective dose'' in particular is a central feature of radiological protection. It sums up any number of different exposures into a single number that reflects, in a general way, the overall risk. The concept may be complex, but it makes radiological protection practical to implement.

===Absorbed Dose===
Absorbed dose is the amount of energy deposited by radiation in a mass.
The mass can be anything: water, rock, air, people, etc.
Absorbed dose is expressed in milligrays (mGy).

Absorbed dose is a measurable, physical quantity. It is expressed in grays (Gy), or, more frequently milligrays (mGy), which are 1/1000th of a gray. 1 gray = 1 joule of energy deposited in 1 kilogram of material i.e. 1 Gy = 1 J/kg

===Equivalent Dose===
Equivalent dose is calculated for individual organs.
It is based on the absorbed dose to an organ, adjusted to account for the effectiveness of the type of radiation.
Equivalent dose is expressed in millisieverts (mSv) to an organ.

Equivalent dose = absorbed Dose multiplied the appropriate radiation weighting factor. The radiation weighting factors are needed because different types of radiation (like alpha, beta, gamma, and neutrons) can have different effects even if the absorbed dose is the same. Equivalent dose is expressed in sieverts (Sv), or, more frequently, millisieverts (mSv) which are 1/1000th of a sievert, and the organ should always be specified (for example "25 mSv to the skin"). In the simplest cases, for gamma (photon) and beta (electron) radiation, the radiation weighting factor is 1, and therefore, for example, an absorbed dose of 1 mGy in an organ equals an equivalent dose of 1 mSv to that organ.

===Effective Dose===
Effective dose is calculated for the whole body. It is sometimes called whole-body dose.
It is the addition of equivalent doses to all organs, each adjusted to account for the sensitivity of the organ to radiation.
Effective dose is expressed in millisieverts (mSv).

Effective dose = sum for all organs of (equivalent dose to the organ times the appropriate tissue weighting factor)
The tissue weighting factors are needed because different organs have different levels of sensitivity to radiation, even if the equivalent dose is the same. Effective dose is expressed in sieverts (Sv), or, more frequently, millisieverts (mSv) which are 1/1000th of a sievert. This is the most frequently used dose in radiological protection. Unless you see mention of a specific organ, a "dose" in Sv or mSv is the effective dose. In the simplest cases, for uniform whole-body exposure to gamma (photon) or beta (electron) radiation, the radiation weighting factor is 1, and the tissue weighting factors add up to 1, and therefore, for example, an absorbed dose of 1 mGy equals an effective dose of 1 mSv.

==Dose Limits==
'''Dose limits help ensure that no person is exposed to an excessive amount of [[ICRPædia Guide to the Basics of Ionising Radiation|radiation]] in normal, planned situations.'''

They are the strongest form of restriction on dose to an individual. Exceeding a dose limit is contrary to regulations in most countries.

 

{| border="1" style="border-collapse: collapse; line-height: 1.4em; height: 450px;"
|+<center> '''Dose Limits Recommended by ICRP''' </center>
! style="width: 30%;" | Type of Dose Limit
! style="width: 30%;" | Limit on Dose from [[System_of_radiation_protection_module_2#Exposure Categories and Situations | Occupational Exposure]]
! style="width: 30%;" | Limit on Dose from [[System_of_radiation_protection_module_2#Exposure Categories and Situations | Public Exposure]]
|-
|[[System_of_radiation_protection_module_2#Effective Dose | Effective Dose]]
|20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv After a worker declares a pregnancy, the dose to the embryo/fetus should not exceed about 1 mSv during the remainder of the pregnancy 
|1 mSv in a year In special circumstances, a higher value could be allowed in a single year, provided that the average over 5 years does not exceed 1 mSv per year 
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Lens of the Eye
|20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv 
|15 mSv in a year
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Skin Averaged over 1 cm2 of skin regardless of the area exposed 
|500 mSv in a year
|50 mSv in a year
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Hands and Feet
|500 mSv in a year
| -
|}
{|span style="font-size:85%; line-height: 1.1em;"
|''Dose limits are primarily from [[ICRP Publication 103]] Table 6. The recommendation for pregnant workers is from [[ICRP Publication 103]] Paragraph 186. The occupational limit for the lens of the eye is from Paragraph 3 of the ICRP Statement on Tissue Reactions in [[ICRP Publication 118]].

''
|}

Dose limits alone are not enough to ensure adequate protection. They function in combination with the [[System_Of_Radiation_Protection_Overview#Fundamental Principles of Radiological Protection | fundamental principles]] of justification and optimisation.

These limits apply only to doses received above the normal local [[Sources of Radiation Exposure | natural background radiation]].

Limits on [[System_of_radiation_protection_module_2#Effective Dose | effective dose]], combined with optimisation of protection, are designed to avoid a risk of [[Effects of Exposure | stochastic effects]] that would be considered intolerable in a [[System_of_radiation_protection_module_2#Exposure Categories and Situations | planned exposure situation]].

Limits on [[System_of_radiation_protection_module_2#Equivalent Dose | equivalent dose to an organ]], combined with optimisation of protection, are designed to prevent the occurance of [[Effects of Exposure | deterministic effects]].

Dose limits apply only in [[System_of_radiation_protection_module_2#Exposure Categories and Situations | planned exposure situations]]. In other situations, restrictions on individual dose are called reference levels. They provide the additional flexibility needed in [[System_of_radiation_protection_module_2#Exposure Categories and Situations | emergency and existing exposure situations]] to make sure protection is optimised.

Dose limits do not apply to [[System_of_radiation_protection_module_2#Exposure Categories and Situations | medical exposures]]. If they did, the effectiveness of diagnosis or treatment might be reduced, doing more harm than good for the patient. The emphasis is on justification of medical procedures and optimisation of protection.

System of radiation protection module 2

2019-10-24T15:50:08Z

Karen Clement: /* Dose Limits */

[[#top| ]]
__FORCETOC__
[[File:ICRPGuide.JPG|150px|thumb|right|link==Guide_to_the_System_of_Radiological_Protection|Take me back to the ICRP's [[Guide_to_the_System_of_Radiological_Protection|Guide to the System of Radiological Protection]]!]]

Introduction

==Exposure Categories and Situations==
 
'''Categories of exposure and exposure situations are used to consider how best to approach radiological protection in different circumstances.'''

Exposure Categories are: occupational, public, and medical.

Exposure Situations are: planned, existing, and emergency.

Categories and Situations are considered together to help guide the best approach to radiological protection in a particular circumstance.

{| class="wikitable"
| style="height: 80px;" |
! [[Image: OccupationalE.png |40px|link=]]

[[Glossary#Occupational Exposure | Occupational Exposure]]

''Exposure of workers incurred as a result of their work''

! [[Image: PublicE.png|40px|link=]]

[[Glossary#Public Exposure | Public Exposure]]

''Exposure of members of the public other than occupational and medical exposures, and not including the normal local natural background radiation''

! [[Image: MedicalE.png |40px|link=]]

[[Glossary#Medical Exposure | Medical Exposure]]

''Exposure of patients as part of their diagnosis or treatment, volunteers helping in the support and comfort of patients, and volunteers in biomedical research
''

|-
! [[Image: PlannedES.png |40px|link=]]

[[Glossary#Planned Exposure Situation | Planned Exposure Situation]]

''Situations where radiological protection can be planned in advance, and exposures can be reasonably predicted''

| style="height: 80px;" | e.g. working in a hospital, uranium mine, or nuclear power plant
| e.g. visiting a hospital, living near a nuclear power plant
| e.g. getting an x-ray, CT scan, or radiation treatment
|-
! [[Image: ExistingES.png |40px|link=]]

[[Glossary#Existing Exposure Situation | Existing Exposure Situation]]

''Situations that already exist when a decision on control has to be taken''

| style="height: 80px;" | e.g. aircrew and astronauts exposed to [[Cosmic Radiation in Aviation | cosmic radiation]]
| e.g. [[Exposure to Radon at Home | radon gas in the home]]
| n/a
|-
! [[Image: EmergencyES.png |40px|link=]]

[[Glossary#Emergency Exposure Situation | Emergency Exposure Situation]]

''Unexpected situations that may require urgent protective actions''

| style="height: 80px;" | e.g. in the immediate response to an accident
| e.g. during a major accident
| n/a
|}

==Radiation Dose==

Radiation dose is a measure of the amount of exposure to radiation. There are three kinds of dose in radiological protection. ''Absorbed dose'' is a measureable, physical quantity, while ''equivalent dose'' and ''effective dose'' are specifically for radiological protection purposes.

''Effective dose'' in particular is a central feature of radiological protection. It sums up any number of different exposures into a single number that reflects, in a general way, the overall risk. The concept may be complex, but it makes radiological protection practical to implement.

===Absorbed Dose===
Absorbed dose is the amount of energy deposited by radiation in a mass.
The mass can be anything: water, rock, air, people, etc.
Absorbed dose is expressed in milligrays (mGy).

Absorbed dose is a measurable, physical quantity. It is expressed in grays (Gy), or, more frequently milligrays (mGy), which are 1/1000th of a gray. 1 gray = 1 joule of energy deposited in 1 kilogram of material i.e. 1 Gy = 1 J/kg

===Equivalent Dose===
Equivalent dose is calculated for individual organs.
It is based on the absorbed dose to an organ, adjusted to account for the effectiveness of the type of radiation.
Equivalent dose is expressed in millisieverts (mSv) to an organ.

Equivalent dose = absorbed Dose multiplied the appropriate radiation weighting factor. The radiation weighting factors are needed because different types of radiation (like alpha, beta, gamma, and neutrons) can have different effects even if the absorbed dose is the same. Equivalent dose is expressed in sieverts (Sv), or, more frequently, millisieverts (mSv) which are 1/1000th of a sievert, and the organ should always be specified (for example "25 mSv to the skin"). In the simplest cases, for gamma (photon) and beta (electron) radiation, the radiation weighting factor is 1, and therefore, for example, an absorbed dose of 1 mGy in an organ equals an equivalent dose of 1 mSv to that organ.

===Effective Dose===
Effective dose is calculated for the whole body. It is sometimes called whole-body dose.
It is the addition of equivalent doses to all organs, each adjusted to account for the sensitivity of the organ to radiation.
Effective dose is expressed in millisieverts (mSv).

Effective dose = sum for all organs of (equivalent dose to the organ times the appropriate tissue weighting factor)
The tissue weighting factors are needed because different organs have different levels of sensitivity to radiation, even if the equivalent dose is the same. Effective dose is expressed in sieverts (Sv), or, more frequently, millisieverts (mSv) which are 1/1000th of a sievert. This is the most frequently used dose in radiological protection. Unless you see mention of a specific organ, a "dose" in Sv or mSv is the effective dose. In the simplest cases, for uniform whole-body exposure to gamma (photon) or beta (electron) radiation, the radiation weighting factor is 1, and the tissue weighting factors add up to 1, and therefore, for example, an absorbed dose of 1 mGy equals an effective dose of 1 mSv.

==Dose Limits==
'''Dose limits help ensure that no person is exposed to an excessive amount of [[ICRPædia Guide to the Basics of Ionising Radiation|radiation]] in normal, planned situations.'''

They are the strongest form of restriction on dose to an individual. Exceeding a dose limit is contrary to regulations in most countries.

 

{| border="1" style="border-collapse: collapse; line-height: 1.4em; height: 450px;"
|+<center> '''Dose Limits Recommended by ICRP''' </center>
! style="width: 30%;" | Type of Dose Limit
! style="width: 30%;" | Limit on Dose from [[System_of_radiation_protection_module_2#Exposure Categories and Situations | Occupational Exposure]]
! style="width: 30%;" | Limit on Dose from [[System_of_radiation_protection_module_2#Exposure Categories and Situations | Public Exposure]]
|-
|[[System_of_radiation_protection_module_2#Effective Dose | Effective Dose]]
|20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv After a worker declares a pregnancy, the dose to the embryo/fetus should not exceed about 1 mSv during the remainder of the pregnancy 
|1 mSv in a year In special circumstances, a higher value could be allowed in a single year, provided that the average over 5 years does not exceed 1 mSv per year 
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Lens of the Eye
|20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv 
|15 mSv in a year
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Skin Averaged over 1 cm2 of skin regardless of the area exposed 
|500 mSv in a year
|50 mSv in a year
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Hands and Feet
|500 mSv in a year
| -
|}
{|span style="font-size:85%; line-height: 1.1em;"
|''Dose limits are primarily from [[ICRP Publication 103]] Table 6. The recommendation for pregnant workers is from [[ICRP Publication 103]] Paragraph 186. The occupational limit for the lens of the eye is from Paragraph 3 of the ICRP Statement on Tissue Reactions in [[ICRP Publication 118]].

''
|}

Dose limits alone are not enough to ensure adequate protection. They function in combination with the [[System_Of_Radiation_Protection_Overview#Fundamental Principles of Radiological Protection | fundamental principles]] of justification and optimisation.

These limits apply only to doses received above the normal local [[Sources of Radiation Exposure | natural background radiation]].

Limits on [[System_of_radiation_protection_module_2#Effective Dose | effective dose]], combined with optimisation of protection, are designed to avoid a risk of [[Effects of Exposure | stochastic effects]] that would be considered intolerable in a [[System_of_radiation_protection_module_2#Exposure Categories and Situations | planned exposure situation]].

Limits on [[System_of_radiation_protection_module_2#Equivalent Dose | equivalent dose to an organ]], combined with optimisation of protection, are designed to prevent the occurance of [[Effects of Exposure | deterministic effects]].

Dose limits apply only in [[System_of_radiation_protection_module_2#Exposure Categories and Situations | planned exposure situations]]. In other situations, restrictions on individual dose are called reference levels. They provide the additional flexibility needed in [[System_of_radiation_protection_module_2#Exposure Categories and Situations | emergency and existing exposure situations]] to make sure protection is optimised.

Dose limits do not apply to [[System_of_radiation_protection_module_2#Exposure Categories and Situations | medical exposures]]. If they did, the effectiveness of diagnosis or treatment might be reduced, doing more harm than good for the patient. The emphasis is on justification of medical procedures and optimisation of protection.

System of radiation protection module 2

2019-10-24T15:48:34Z

Karen Clement: /* Dose Limits */

[[#top| ]]
__FORCETOC__
[[File:ICRPGuide.JPG|150px|thumb|right|link==Guide_to_the_System_of_Radiological_Protection|Take me back to the ICRP's [[Guide_to_the_System_of_Radiological_Protection|Guide to the System of Radiological Protection]]!]]

Introduction

==Exposure Categories and Situations==
 
'''Categories of exposure and exposure situations are used to consider how best to approach radiological protection in different circumstances.'''

Exposure Categories are: occupational, public, and medical.

Exposure Situations are: planned, existing, and emergency.

Categories and Situations are considered together to help guide the best approach to radiological protection in a particular circumstance.

{| class="wikitable"
| style="height: 80px;" |
! [[Image: OccupationalE.png |40px|link=]]

[[Glossary#Occupational Exposure | Occupational Exposure]]

''Exposure of workers incurred as a result of their work''

! [[Image: PublicE.png|40px|link=]]

[[Glossary#Public Exposure | Public Exposure]]

''Exposure of members of the public other than occupational and medical exposures, and not including the normal local natural background radiation''

! [[Image: MedicalE.png |40px|link=]]

[[Glossary#Medical Exposure | Medical Exposure]]

''Exposure of patients as part of their diagnosis or treatment, volunteers helping in the support and comfort of patients, and volunteers in biomedical research
''

|-
! [[Image: PlannedES.png |40px|link=]]

[[Glossary#Planned Exposure Situation | Planned Exposure Situation]]

''Situations where radiological protection can be planned in advance, and exposures can be reasonably predicted''

| style="height: 80px;" | e.g. working in a hospital, uranium mine, or nuclear power plant
| e.g. visiting a hospital, living near a nuclear power plant
| e.g. getting an x-ray, CT scan, or radiation treatment
|-
! [[Image: ExistingES.png |40px|link=]]

[[Glossary#Existing Exposure Situation | Existing Exposure Situation]]

''Situations that already exist when a decision on control has to be taken''

| style="height: 80px;" | e.g. aircrew and astronauts exposed to [[Cosmic Radiation in Aviation | cosmic radiation]]
| e.g. [[Exposure to Radon at Home | radon gas in the home]]
| n/a
|-
! [[Image: EmergencyES.png |40px|link=]]

[[Glossary#Emergency Exposure Situation | Emergency Exposure Situation]]

''Unexpected situations that may require urgent protective actions''

| style="height: 80px;" | e.g. in the immediate response to an accident
| e.g. during a major accident
| n/a
|}

==Radiation Dose==

Radiation dose is a measure of the amount of exposure to radiation. There are three kinds of dose in radiological protection. ''Absorbed dose'' is a measureable, physical quantity, while ''equivalent dose'' and ''effective dose'' are specifically for radiological protection purposes.

''Effective dose'' in particular is a central feature of radiological protection. It sums up any number of different exposures into a single number that reflects, in a general way, the overall risk. The concept may be complex, but it makes radiological protection practical to implement.

===Absorbed Dose===
Absorbed dose is the amount of energy deposited by radiation in a mass.
The mass can be anything: water, rock, air, people, etc.
Absorbed dose is expressed in milligrays (mGy).

Absorbed dose is a measurable, physical quantity. It is expressed in grays (Gy), or, more frequently milligrays (mGy), which are 1/1000th of a gray. 1 gray = 1 joule of energy deposited in 1 kilogram of material i.e. 1 Gy = 1 J/kg

===Equivalent Dose===
Equivalent dose is calculated for individual organs.
It is based on the absorbed dose to an organ, adjusted to account for the effectiveness of the type of radiation.
Equivalent dose is expressed in millisieverts (mSv) to an organ.

Equivalent dose = absorbed Dose multiplied the appropriate radiation weighting factor. The radiation weighting factors are needed because different types of radiation (like alpha, beta, gamma, and neutrons) can have different effects even if the absorbed dose is the same. Equivalent dose is expressed in sieverts (Sv), or, more frequently, millisieverts (mSv) which are 1/1000th of a sievert, and the organ should always be specified (for example "25 mSv to the skin"). In the simplest cases, for gamma (photon) and beta (electron) radiation, the radiation weighting factor is 1, and therefore, for example, an absorbed dose of 1 mGy in an organ equals an equivalent dose of 1 mSv to that organ.

===Effective Dose===
Effective dose is calculated for the whole body. It is sometimes called whole-body dose.
It is the addition of equivalent doses to all organs, each adjusted to account for the sensitivity of the organ to radiation.
Effective dose is expressed in millisieverts (mSv).

Effective dose = sum for all organs of (equivalent dose to the organ times the appropriate tissue weighting factor)
The tissue weighting factors are needed because different organs have different levels of sensitivity to radiation, even if the equivalent dose is the same. Effective dose is expressed in sieverts (Sv), or, more frequently, millisieverts (mSv) which are 1/1000th of a sievert. This is the most frequently used dose in radiological protection. Unless you see mention of a specific organ, a "dose" in Sv or mSv is the effective dose. In the simplest cases, for uniform whole-body exposure to gamma (photon) or beta (electron) radiation, the radiation weighting factor is 1, and the tissue weighting factors add up to 1, and therefore, for example, an absorbed dose of 1 mGy equals an effective dose of 1 mSv.

==Dose Limits==
'''Dose limits help ensure that no person is exposed to an excessive amount of [[ICRPædia Guide to the Basics of Ionising Radiation|radiation]] in normal, planned situations.'''

They are the strongest form of restriction on dose to an individual. Exceeding a dose limit is contrary to regulations in most countries.

 

{| border="1" style="border-collapse: collapse; line-height: 1.4em; height: 450px;"
|+<center> '''Dose Limits Recommended by ICRP''' </center>
! style="width: 30%;" | Type of Dose Limit
! style="width: 30%;" | Limit on Dose from [[System_of_radiation_protection_module_2#Exposure Categories and Situations | Occupational Exposure]]
! style="width: 30%;" | Limit on Dose from [[System_of_radiation_protection_module_2#Exposure Categories and Situations | Public Exposure]]
|-
|[[System_of_radiation_protection_module_2#Effective Dose | Effective Dose]]
|20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv After a worker declares a pregnancy, the dose to the embryo/fetus should not exceed about 1 mSv during the remainder of the pregnancy 
|1 mSv in a year In special circumstances, a higher value could be allowed in a single year, provided that the average over 5 years does not exceed 1 mSv per year 
|-
|[[System_of_radiation_protection_module_2#Effective Dose|Equivalent Dose]] to the Lens of the Eye
|20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv 
|15 mSv in a year
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Skin Averaged over 1 cm2 of skin regardless of the area exposed 
|500 mSv in a year
|50 mSv in a year
|-
|[[System_of_radiation_protection_module_2#Equivalent Dose|Equivalent Dose]] to the Hands and Feet
|500 mSv in a year
| -
|}
{|span style="font-size:85%; line-height: 1.1em;"
|''Dose limits are primarily from [[ICRP Publication 103]] Table 6. The recommendation for pregnant workers is from [[ICRP Publication 103]] Paragraph 186. The occupational limit for the lens of the eye is from Paragraph 3 of the ICRP Statement on Tissue Reactions in [[ICRP Publication 118]].

''
|}

Dose limits alone are not enough to ensure adequate protection. They function in combination with the [[System_Of_Radiation_Protection_Overview#Fundamental Principles of Radiological Protection | fundamental principles]] of justification and optimisation.

These limits apply only to doses received above the normal local [[Sources of Radiation Exposure | natural background radiation]].

Limits on [[System_of_radiation_protection_module_2#Effective Dose | effective dose]], combined with optimisation of protection, are designed to avoid a risk of [[Effects of Exposure | stochastic effects]] that would be considered intolerable in a [[System_of_radiation_protection_module_2#Exposure Categories and Situations | planned exposure situation]].

Limits on [[System_of_radiation_protection_module_2#Equivalent Dose | equivalent dose to an organ]], combined with optimisation of protection, are designed to prevent the occurance of [[Effects of Exposure | deterministic effects]].

Dose limits apply only in [[System_of_radiation_protection_module_2#Exposure Categories and Situations | planned exposure situations]]. In other situations, restrictions on individual dose are called reference levels. They provide the additional flexibility needed in [[System_of_radiation_protection_module_2#Exposure Categories and Situations | emergency and existing exposure situations]] to make sure protection is optimised.

Dose limits do not apply to [[System_of_radiation_protection_module_2#Exposure Categories and Situations | medical exposures]]. If they did, the effectiveness of diagnosis or treatment might be reduced, doing more harm than good for the patient. The emphasis is on justification of medical procedures and optimisation of protection.

System Of Radiation Protection Overview

2019-10-24T15:46:50Z

Karen Clement:

System of radiation protection module 2

2019-10-24T15:43:52Z

Karen Clement: /* Dose Limits */

[[#top| ]]
__FORCETOC__
[[File:ICRPGuide.JPG|150px|thumb|right|link==Guide_to_the_System_of_Radiological_Protection|Take me back to the ICRP's [[Guide_to_the_System_of_Radiological_Protection|Guide to the System of Radiological Protection]]!]]

Introduction

==Exposure Categories and Situations==
 
'''Categories of exposure and exposure situations are used to consider how best to approach radiological protection in different circumstances.'''

Exposure Categories are: occupational, public, and medical.

Exposure Situations are: planned, existing, and emergency.

Categories and Situations are considered together to help guide the best approach to radiological protection in a particular circumstance.

{| class="wikitable"
| style="height: 80px;" |
! [[Image: OccupationalE.png |40px|link=]]

[[Glossary#Occupational Exposure | Occupational Exposure]]

''Exposure of workers incurred as a result of their work''

! [[Image: PublicE.png|40px|link=]]

[[Glossary#Public Exposure | Public Exposure]]

''Exposure of members of the public other than occupational and medical exposures, and not including the normal local natural background radiation''

! [[Image: MedicalE.png |40px|link=]]

[[Glossary#Medical Exposure | Medical Exposure]]

''Exposure of patients as part of their diagnosis or treatment, volunteers helping in the support and comfort of patients, and volunteers in biomedical research
''

|-
! [[Image: PlannedES.png |40px|link=]]

[[Glossary#Planned Exposure Situation | Planned Exposure Situation]]

''Situations where radiological protection can be planned in advance, and exposures can be reasonably predicted''

| style="height: 80px;" | e.g. working in a hospital, uranium mine, or nuclear power plant
| e.g. visiting a hospital, living near a nuclear power plant
| e.g. getting an x-ray, CT scan, or radiation treatment
|-
! [[Image: ExistingES.png |40px|link=]]

[[Glossary#Existing Exposure Situation | Existing Exposure Situation]]

''Situations that already exist when a decision on control has to be taken''

| style="height: 80px;" | e.g. aircrew and astronauts exposed to [[Cosmic Radiation in Aviation | cosmic radiation]]
| e.g. [[Exposure to Radon at Home | radon gas in the home]]
| n/a
|-
! [[Image: EmergencyES.png |40px|link=]]

[[Glossary#Emergency Exposure Situation | Emergency Exposure Situation]]

''Unexpected situations that may require urgent protective actions''

| style="height: 80px;" | e.g. in the immediate response to an accident
| e.g. during a major accident
| n/a
|}

==Radiation Dose==

Radiation dose is a measure of the amount of exposure to radiation. There are three kinds of dose in radiological protection. ''Absorbed dose'' is a measureable, physical quantity, while ''equivalent dose'' and ''effective dose'' are specifically for radiological protection purposes.

''Effective dose'' in particular is a central feature of radiological protection. It sums up any number of different exposures into a single number that reflects, in a general way, the overall risk. The concept may be complex, but it makes radiological protection practical to implement.

===Absorbed Dose===
Absorbed dose is the amount of energy deposited by radiation in a mass.
The mass can be anything: water, rock, air, people, etc.
Absorbed dose is expressed in milligrays (mGy).

Absorbed dose is a measurable, physical quantity. It is expressed in grays (Gy), or, more frequently milligrays (mGy), which are 1/1000th of a gray. 1 gray = 1 joule of energy deposited in 1 kilogram of material i.e. 1 Gy = 1 J/kg

===Equivalent Dose===
Equivalent dose is calculated for individual organs.
It is based on the absorbed dose to an organ, adjusted to account for the effectiveness of the type of radiation.
Equivalent dose is expressed in millisieverts (mSv) to an organ.

Equivalent dose = absorbed Dose multiplied the appropriate radiation weighting factor. The radiation weighting factors are needed because different types of radiation (like alpha, beta, gamma, and neutrons) can have different effects even if the absorbed dose is the same. Equivalent dose is expressed in sieverts (Sv), or, more frequently, millisieverts (mSv) which are 1/1000th of a sievert, and the organ should always be specified (for example "25 mSv to the skin"). In the simplest cases, for gamma (photon) and beta (electron) radiation, the radiation weighting factor is 1, and therefore, for example, an absorbed dose of 1 mGy in an organ equals an equivalent dose of 1 mSv to that organ.

===Effective Dose===
Effective dose is calculated for the whole body. It is sometimes called whole-body dose.
It is the addition of equivalent doses to all organs, each adjusted to account for the sensitivity of the organ to radiation.
Effective dose is expressed in millisieverts (mSv).

Effective dose = sum for all organs of (equivalent dose to the organ times the appropriate tissue weighting factor)
The tissue weighting factors are needed because different organs have different levels of sensitivity to radiation, even if the equivalent dose is the same. Effective dose is expressed in sieverts (Sv), or, more frequently, millisieverts (mSv) which are 1/1000th of a sievert. This is the most frequently used dose in radiological protection. Unless you see mention of a specific organ, a "dose" in Sv or mSv is the effective dose. In the simplest cases, for uniform whole-body exposure to gamma (photon) or beta (electron) radiation, the radiation weighting factor is 1, and the tissue weighting factors add up to 1, and therefore, for example, an absorbed dose of 1 mGy equals an effective dose of 1 mSv.

==Dose Limits==
'''Dose limits help ensure that no person is exposed to an excessive amount of [[ICRPædia Guide to the Basics of Ionising Radiation|radiation]] in normal, planned situations.'''

They are the strongest form of restriction on dose to an individual. Exceeding a dose limit is contrary to regulations in most countries.

 

{| border="1" style="border-collapse: collapse; line-height: 1.4em; height: 450px;"
|+<center> '''Dose Limits Recommended by ICRP''' </center>
! style="width: 30%;" | Type of Dose Limit
! style="width: 30%;" | Limit on Dose from [[Exposure Categories and Situations | Occupational Exposure]]
! style="width: 30%;" | Limit on Dose from [[Exposure Categories and Situations | Public Exposure]]
|-
|[[Absorbed, Equivalent, and Effective Dose | Effective Dose]]
|20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv After a worker declares a pregnancy, the dose to the embryo/fetus should not exceed about 1 mSv during the remainder of the pregnancy 
|1 mSv in a year In special circumstances, a higher value could be allowed in a single year, provided that the average over 5 years does not exceed 1 mSv per year 
|-
|[[Absorbed, Equivalent, and Effective Dose|Equivalent Dose]] to the Lens of the Eye
|20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv 
|15 mSv in a year
|-
|[[Absorbed, Equivalent, and Effective Dose|Equivalent Dose]] to the Skin Averaged over 1 cm2 of skin regardless of the area exposed 
|500 mSv in a year
|50 mSv in a year
|-
|[[Absorbed, Equivalent, and Effective Dose|Equivalent Dose]] to the Hands and Feet
|500 mSv in a year
| -
|}
{|span style="font-size:85%; line-height: 1.1em;"
|''Dose limits are primarily from [[ICRP Publication 103]] Table 6. The recommendation for pregnant workers is from [[ICRP Publication 103]] Paragraph 186. The occupational limit for the lens of the eye is from Paragraph 3 of the ICRP Statement on Tissue Reactions in [[ICRP Publication 118]].

''
|}

Dose limits alone are not enough to ensure adequate protection. They function in combination with the [[Fundamental Principles of Radiological Protection | fundamental principles]] of justification and optimisation.

These limits apply only to doses received above the normal local [[Sources of Radiation Exposure | natural background radiation]].

Limits on [[System_of_radiation_protection_module_2#Effective Dose | effective dose]], combined with optimisation of protection, are designed to avoid a risk of [[Effects of Exposure | stochastic effects]] that would be considered intolerable in a [[Exposure Categories and Situations | planned exposure situation]].

Limits on [[Absorbed, Equivalent, and Effective Dose | equivalent dose to an organ]], combined with optimisation of protection, are designed to prevent the occurance of [[Effects of Exposure | deterministic effects]].

Dose limits apply only in [[Exposure Categories and Situations | planned exposure situations]]. In other situations, restrictions on individual dose are called reference levels. They provide the additional flexibility needed in [[Exposure Categories and Situations | emergency and existing exposure situations]] to make sure protection is optimised.

Dose limits do not apply to [[Exposure Categories and Situations | medical exposures]]. If they did, the effectiveness of diagnosis or treatment might be reduced, doing more harm than good for the patient. The emphasis is on justification of medical procedures and optimisation of protection.

Guide to the System of Radiological Protection

2019-10-24T15:40:24Z

Karen Clement:

[[#top| ]]
[[File:ICRPGuide.JPG|200px|thumb|right|link=|'''''Welcome to ICRP's guide to the System of Radiological Protection!''''' '' When you're in the guide look for me and I can take you back here if you want to dive into a new module.'']]

Intro

To start click on one of the modules below!
<div>
<ul mode=nolines>
<li style="display: inline-block; vertical-align: top;">
[[File:System_Of_Radiation_Protection_Overview.jpg|border|none|200px|link=System_Of_Radiation_Protection_Overview]]
</li>

<li style="display: inline-block; vertical-align: top;">
[[File:Radon_For_Homeowners_And_Residents-2.jpg|border|none|200px|link=System_of_radiation_protection_module_2]]
</li>

</div>

System of radiation protection module 2

2019-10-24T15:39:21Z

[[#top| ]]
__FORCETOC__
[[File:ICRPGuide.JPG|150px|thumb|right|link==Guide_to_the_System_of_Radiological_Protection|Take me back to the ICRP's [[Guide_to_the_System_of_Radiological_Protection|Guide to the System of Radiological Protection]]!]]

Introduction

==Exposure Categories and Situations==
 
'''Categories of exposure and exposure situations are used to consider how best to approach radiological protection in different circumstances.'''

Exposure Categories are: occupational, public, and medical.

Exposure Situations are: planned, existing, and emergency.

Categories and Situations are considered together to help guide the best approach to radiological protection in a particular circumstance.

{| class="wikitable"
| style="height: 80px;" |
! [[Image: OccupationalE.png |40px|link=]]

[[Glossary#Occupational Exposure | Occupational Exposure]]

''Exposure of workers incurred as a result of their work''

! [[Image: PublicE.png|40px|link=]]

[[Glossary#Public Exposure | Public Exposure]]

''Exposure of members of the public other than occupational and medical exposures, and not including the normal local natural background radiation''

! [[Image: MedicalE.png |40px|link=]]

[[Glossary#Medical Exposure | Medical Exposure]]

''Exposure of patients as part of their diagnosis or treatment, volunteers helping in the support and comfort of patients, and volunteers in biomedical research
''

|-
! [[Image: PlannedES.png |40px|link=]]

[[Glossary#Planned Exposure Situation | Planned Exposure Situation]]

''Situations where radiological protection can be planned in advance, and exposures can be reasonably predicted''

| style="height: 80px;" | e.g. working in a hospital, uranium mine, or nuclear power plant
| e.g. visiting a hospital, living near a nuclear power plant
| e.g. getting an x-ray, CT scan, or radiation treatment
|-
! [[Image: ExistingES.png |40px|link=]]

[[Glossary#Existing Exposure Situation | Existing Exposure Situation]]

''Situations that already exist when a decision on control has to be taken''

| style="height: 80px;" | e.g. aircrew and astronauts exposed to [[Cosmic Radiation in Aviation | cosmic radiation]]
| e.g. [[Exposure to Radon at Home | radon gas in the home]]
| n/a
|-
! [[Image: EmergencyES.png |40px|link=]]

[[Glossary#Emergency Exposure Situation | Emergency Exposure Situation]]

''Unexpected situations that may require urgent protective actions''

| style="height: 80px;" | e.g. in the immediate response to an accident
| e.g. during a major accident
| n/a
|}

==Radiation Dose==

Radiation dose is a measure of the amount of exposure to radiation. There are three kinds of dose in radiological protection. ''Absorbed dose'' is a measureable, physical quantity, while ''equivalent dose'' and ''effective dose'' are specifically for radiological protection purposes.

''Effective dose'' in particular is a central feature of radiological protection. It sums up any number of different exposures into a single number that reflects, in a general way, the overall risk. The concept may be complex, but it makes radiological protection practical to implement.

===Absorbed Dose===
Absorbed dose is the amount of energy deposited by radiation in a mass.
The mass can be anything: water, rock, air, people, etc.
Absorbed dose is expressed in milligrays (mGy).

Absorbed dose is a measurable, physical quantity. It is expressed in grays (Gy), or, more frequently milligrays (mGy), which are 1/1000th of a gray. 1 gray = 1 joule of energy deposited in 1 kilogram of material i.e. 1 Gy = 1 J/kg

===Equivalent Dose===
Equivalent dose is calculated for individual organs.
It is based on the absorbed dose to an organ, adjusted to account for the effectiveness of the type of radiation.
Equivalent dose is expressed in millisieverts (mSv) to an organ.

Equivalent dose = absorbed Dose multiplied the appropriate radiation weighting factor. The radiation weighting factors are needed because different types of radiation (like alpha, beta, gamma, and neutrons) can have different effects even if the absorbed dose is the same. Equivalent dose is expressed in sieverts (Sv), or, more frequently, millisieverts (mSv) which are 1/1000th of a sievert, and the organ should always be specified (for example "25 mSv to the skin"). In the simplest cases, for gamma (photon) and beta (electron) radiation, the radiation weighting factor is 1, and therefore, for example, an absorbed dose of 1 mGy in an organ equals an equivalent dose of 1 mSv to that organ.

===Effective Dose===
Effective dose is calculated for the whole body. It is sometimes called whole-body dose.
It is the addition of equivalent doses to all organs, each adjusted to account for the sensitivity of the organ to radiation.
Effective dose is expressed in millisieverts (mSv).

Effective dose = sum for all organs of (equivalent dose to the organ times the appropriate tissue weighting factor)
The tissue weighting factors are needed because different organs have different levels of sensitivity to radiation, even if the equivalent dose is the same. Effective dose is expressed in sieverts (Sv), or, more frequently, millisieverts (mSv) which are 1/1000th of a sievert. This is the most frequently used dose in radiological protection. Unless you see mention of a specific organ, a "dose" in Sv or mSv is the effective dose. In the simplest cases, for uniform whole-body exposure to gamma (photon) or beta (electron) radiation, the radiation weighting factor is 1, and the tissue weighting factors add up to 1, and therefore, for example, an absorbed dose of 1 mGy equals an effective dose of 1 mSv.

==Dose Limits==
'''Dose limits help ensure that no person is exposed to an excessive amount of [[ICRPædia Guide to the Basics of Ionising Radiation|radiation]] in normal, planned situations.'''

They are the strongest form of restriction on dose to an individual. Exceeding a dose limit is contrary to regulations in most countries.

 

{| border="1" style="border-collapse: collapse; line-height: 1.4em; height: 450px;"
|+<center> '''Dose Limits Recommended by ICRP''' </center>
! style="width: 30%;" | Type of Dose Limit
! style="width: 30%;" | Limit on Dose from [[Exposure Categories and Situations | Occupational Exposure]]
! style="width: 30%;" | Limit on Dose from [[Exposure Categories and Situations | Public Exposure]]
|-
|[[Absorbed, Equivalent, and Effective Dose | Effective Dose]]
|20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv After a worker declares a pregnancy, the dose to the embryo/fetus should not exceed about 1 mSv during the remainder of the pregnancy 
|1 mSv in a year In special circumstances, a higher value could be allowed in a single year, provided that the average over 5 years does not exceed 1 mSv per year 
|-
|[[Absorbed, Equivalent, and Effective Dose|Equivalent Dose]] to the Lens of the Eye
|20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv 
|15 mSv in a year
|-
|[[Absorbed, Equivalent, and Effective Dose|Equivalent Dose]] to the Skin Averaged over 1 cm2 of skin regardless of the area exposed 
|500 mSv in a year
|50 mSv in a year
|-
|[[Absorbed, Equivalent, and Effective Dose|Equivalent Dose]] to the Hands and Feet
|500 mSv in a year
| -
|}
{|span style="font-size:85%; line-height: 1.1em;"
|''Dose limits are primarily from [[ICRP Publication 103]] Table 6. The recommendation for pregnant workers is from [[ICRP Publication 103]] Paragraph 186. The occupational limit for the lens of the eye is from Paragraph 3 of the ICRP Statement on Tissue Reactions in [[ICRP Publication 118]].

''
|}

Dose limits alone are not enough to ensure adequate protection. They function in combination with the [[Fundamental Principles of Radiological Protection | fundamental principles]] of justification and optimisation.

These limits apply only to doses received above the normal local [[Sources of Radiation Exposure | natural background radiation]].

Limits on [[Absorbed, Equivalent, and Effective Dose | effective dose]], combined with optimisation of protection, are designed to avoid a risk of [[Effects of Exposure | stochastic effects]] that would be considered intolerable in a [[Exposure Categories and Situations | planned exposure situation]].

Limits on [[Absorbed, Equivalent, and Effective Dose | equivalent dose to an organ]], combined with optimisation of protection, are designed to prevent the occurance of [[Effects of Exposure | deterministic effects]].

Dose limits apply only in [[Exposure Categories and Situations | planned exposure situations]]. In other situations, restrictions on individual dose are called reference levels. They provide the additional flexibility needed in [[Exposure Categories and Situations | emergency and existing exposure situations]] to make sure protection is optimised.

Dose limits do not apply to [[Exposure Categories and Situations | medical exposures]]. If they did, the effectiveness of diagnosis or treatment might be reduced, doing more harm than good for the patient. The emphasis is on justification of medical procedures and optimisation of protection.

System Of Radiation Protection Overview

2019-10-24T13:27:21Z

Karen Clement: /* What is the System of Radiological Protection? */

System Of Radiation Protection Overview

2019-10-24T13:27:12Z

Karen Clement: /* Objectives of Radiological Protection */

System Of Radiation Protection Overview

2019-10-24T13:26:50Z

Karen Clement: /* Fundamental Principles of Radiological Protection */

System Of Radiation Protection Overview

2019-10-24T13:26:01Z

Karen Clement: /* Fundamental Principles of Radiological Protection */

System Of Radiation Protection Overview

2019-10-24T13:22:16Z

Karen Clement: /* Objectives of Radiological Protection */

System Of Radiation Protection Overview

2019-10-24T13:21:50Z

Karen Clement: /* Objectives of Radiological Protection */