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Created page with "<span style= "font-size:115%;"> '''Dose limits help ensure that no person is exposed to an excessive amount of [[ICRPædia Guide to the Basics of Ionising Radiation|radiation]..."
<span style= "font-size:115%;"> '''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.''' </span>
They are the strongest form of restriction on dose to an individual. Exceeding a dose limit is contrary to regulations in most countries.
<br>
<br>
{| border="1" style="border-collapse: collapse; line-height: 1.4em; height: 450px;"
|+<center> <span style="color:#4682B4; font-size: 110%;"> '''Dose Limits Recommended by ICRP''' </span> </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 <br /> <span style= "font-size:70%;"> After a worker declares a pregnancy, the dose to the embryo/fetus should not exceed about 1 mSv during the remainder of the pregnancy </span>
|1 mSv in a year <br /> <span style= "font-size:70%;"> 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 </span>
|-
|[[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 <br />
|15 mSv in a year
|-
|[[Absorbed, Equivalent, and Effective Dose|Equivalent Dose]] to the Skin <br /> <span style= "font-size:70%;"> Averaged over 1 cm<sup>2</sup> of skin regardless of the area exposed </span>
|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.
==<span class="mw-collapsible-headline">Quotes from ICRP Publications</span>==
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<div class="mw-collapsible-toggle"><span style="color:#ffffff;">[see more/less]</span></div>
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'''''[[ICRP Publication 103]]'' paragraph 243'''
<blockquote>Dose limits apply only in planned exposure situations but not to medical exposures of patients. ... dose limits ... recommended in Publication 60 ... continue to provide an appropriate level of protection. ... Within a category of exposure, occupational or public, dose limits apply to the sum of exposures from sources related to practices that are already justified ...</blockquote>
'''''[[ICRP Publication 103]]'' paragraph 247'''
<blockquote>Dose limits do not apply in emergency exposure situations where an informed, exposed individual is engaged in volunteered life-saving actions or is attempting to prevent a catastrophic situation. For informed volunteers undertaking urgent rescue operations, the normal dose restriction may be relaxed ...</blockquote>
'''''[[ICRP Publication 103]]'' paragraph 248'''
<blockquote>For informed individuals of the general public involved in caring and comforting patients released from a hospital following therapy with unsealed radionuclides, the normal dose restriction may be relaxed and such individuals should in general not be subject to the public dose limit ...</blockquote>
'''''[[ICRP Publication 103]]'' paragraph 186'''
<blockquote>... Once an employer has been notified of a pregnancy, additional protection of the embryo/fetus should be considered. The working conditions of a pregnant worker, after declaration of pregnancy, should be such as to ensure that the additional dose to the embryo/fetus would not exceed about 1 mSv during the remainder of the pregnancy ...</blockquote>
</div>
==See Also==
<div>
<ul mode=nolines>
<li style="display: inline-block; vertical-align: top;">
[[File:ICRPGuide.JPG|thumb|none|100px|link=ICRPædia Guide to the System of Radiological Protection|<center>[[ICRPædia Guide to the System of Radiological Protection]]</center>]]
</li>
<li style="display: inline-block; vertical-align: top;">
[[File:Pub103Cover.jpg|thumb|none|100px|link=ICRP Publication 103 |
<center>[[ICRP Publication 103]] The 2007 Recommendations of ICRP</center>]]
</li>
</ul>
</div>
They are the strongest form of restriction on dose to an individual. Exceeding a dose limit is contrary to regulations in most countries.
<br>
<br>
{| border="1" style="border-collapse: collapse; line-height: 1.4em; height: 450px;"
|+<center> <span style="color:#4682B4; font-size: 110%;"> '''Dose Limits Recommended by ICRP''' </span> </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 <br /> <span style= "font-size:70%;"> After a worker declares a pregnancy, the dose to the embryo/fetus should not exceed about 1 mSv during the remainder of the pregnancy </span>
|1 mSv in a year <br /> <span style= "font-size:70%;"> 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 </span>
|-
|[[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 <br />
|15 mSv in a year
|-
|[[Absorbed, Equivalent, and Effective Dose|Equivalent Dose]] to the Skin <br /> <span style= "font-size:70%;"> Averaged over 1 cm<sup>2</sup> of skin regardless of the area exposed </span>
|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.
==<span class="mw-collapsible-headline">Quotes from ICRP Publications</span>==
<div id="collapse02" class="mw-collapsible mw-collapsed">
<div class="mw-collapsible-toggle">
<div class="mw-collapsible-toggle-row">
<div class="mw-collapsible-toggle"><span style="color:#ffffff;">[see more/less]</span></div>
</div>
</div>
<br />
<div class="mw-collapsible-content">
'''''[[ICRP Publication 103]]'' paragraph 243'''
<blockquote>Dose limits apply only in planned exposure situations but not to medical exposures of patients. ... dose limits ... recommended in Publication 60 ... continue to provide an appropriate level of protection. ... Within a category of exposure, occupational or public, dose limits apply to the sum of exposures from sources related to practices that are already justified ...</blockquote>
'''''[[ICRP Publication 103]]'' paragraph 247'''
<blockquote>Dose limits do not apply in emergency exposure situations where an informed, exposed individual is engaged in volunteered life-saving actions or is attempting to prevent a catastrophic situation. For informed volunteers undertaking urgent rescue operations, the normal dose restriction may be relaxed ...</blockquote>
'''''[[ICRP Publication 103]]'' paragraph 248'''
<blockquote>For informed individuals of the general public involved in caring and comforting patients released from a hospital following therapy with unsealed radionuclides, the normal dose restriction may be relaxed and such individuals should in general not be subject to the public dose limit ...</blockquote>
'''''[[ICRP Publication 103]]'' paragraph 186'''
<blockquote>... Once an employer has been notified of a pregnancy, additional protection of the embryo/fetus should be considered. The working conditions of a pregnant worker, after declaration of pregnancy, should be such as to ensure that the additional dose to the embryo/fetus would not exceed about 1 mSv during the remainder of the pregnancy ...</blockquote>
</div>
==See Also==
<div>
<ul mode=nolines>
<li style="display: inline-block; vertical-align: top;">
[[File:ICRPGuide.JPG|thumb|none|100px|link=ICRPædia Guide to the System of Radiological Protection|<center>[[ICRPædia Guide to the System of Radiological Protection]]</center>]]
</li>
<li style="display: inline-block; vertical-align: top;">
[[File:Pub103Cover.jpg|thumb|none|100px|link=ICRP Publication 103 |
<center>[[ICRP Publication 103]] The 2007 Recommendations of ICRP</center>]]
</li>
</ul>
</div>
