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Calculating Radon Doses

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<span style="font-size:115%;"> '''Radon levels (in [[Radon: Units of Measure|Bq/m<sup>3</sup>]]) 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.''' </span>

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/m<sup>3</sup>]]) 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/m<sup>3</sup>]] 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/m<sup>3</sup>]] of radon for one year at work gives an [[Absorbed, Equivalent, and Effective Dose|effective dose]] of 1.4 mSv.



Please see the Expert Summary for more details.



==<span class="mw-collapsible-headline">Details</span>==

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'''Radon Protection Strategy: ''Publication 126'' paragraphs 41-45'''
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In most circumstances, ICRP recommends a dose coefficient of 3 mSv per mJ h m<sup>-3</sup>. Using the standard equilibrium factor assumption of F = 0.4 (the ratio between the concentration of radon progeny and radon-222) for most situations, this corresponds to 6.9 x 10<sup>-6</sup> mSv per Bq h m<sup>-3</sup>.

For work indoors involving substantial physical activity, and exposures in tourist caves, ICRP recommends 6 mSv per mJ h m<sup>-3</sup>. Using the standard equilibrium factor assumption of F = 0.4, this corresponds to 1.4 x 10<sup>-5</sup> mSv per Bq h m<sup>-3</sup>.

Where aerosol characteristics are significantly different from typical conditions; sufficient, reliable aerosol data are available, and estimated doses warrant more detailed consideration, it is possible to calculate site-specific dose coefficients using data provided in ICRP Publication 137.
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==<span class="mw-collapsible-headline">Quotes from ICRP Publications</span>==

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'''Occupational Intakes of Radionuclides, Part 3: ''Publication 137'' paragraphs 57-60'''


: The present situation is a remarkable consistency between coefficients obtained by dosimetric calculations and conversion coefficients based on epidemiological comparisons…
For the calculation of doses following inhalation of radon and radon progeny in most circumstances, the Commission recommends a dose coefficient of 3 mSv per mJ h m-3 (approximately 10 mSv per WLM). The Commission considers this dose coefficient to be applicable to the majority of circumstances with no adjustment for aerosol characteristics. The corresponding dose coefficient expressed in terms of radon-222 gas exposure depends on the equilibrium factor, F, between radon gas and its progeny. Using the standard assumption of F = 0.4 for most situations, 3 mSv per mJ h m-3 corresponds to 6.9 x 10-6 mSv per Bq h m-3.

For the specific situations of work indoors involving substantial physical activity, and exposures in tourist caves, the Commission recommends a dose coefficient of 6 mSv per mJ h m-3 (approximately 20 mSv per WLM). Using the standard assumption of F = 0.4 for most situations, 6 mSv per mJ h m-3 corresponds to 1.4 x 10-5 mSv per Bq h m-3.
In cases where aerosol characteristics are significantly different from typical conditions; sufficient, reliable aerosol data are available; and, estimated doses warrant more detailed consideration, it is possible to calculate site-specific dose coefficients using the data provided…

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==See Also==
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<li style="display: inline-block; vertical-align: top;">
[[File:ICRPGuide.JPG|thumb|none|100px|link=ICRPædia Guide to Radon|<center>[[ICRPædia Guide to Radon]]</center>]]
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[[File:ICRPGuide.JPG|thumb|none|100px|link=ICRPædia Guide to Dose Coefficients |
<center>[[ICRPædia Guide to Dose Coefficients]]</center>]]
</li>

<li style="display: inline-block; vertical-align: top;">
[[File:RadonSeeAlso2.jpg|thumb|none|250px|link={{filepath:ICRPRadonSummary.pdf}}| <center>[[Media:ICRPRadonSummary.pdf |Expert Summary of ICRP Recommendations on Radon]]</center>]]
</li>

<li style="display: inline-block; vertical-align: top;">
[[File:RadonSeeAlso4.jpg|thumb|none|200px|link=http://www.icrp.org/publication.asp?id=ICRP%20Publication%20137|<center>[http://www.icrp.org/publication.asp?id=ICRP%20Publication%20137 ICRP ''Publication'' 137 Occupational Intakes of Radionuclides: Part 3]</center>]]
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<li style="display: inline-block; vertical-align: top;">
[[File:RadonSeeAlso3.jpg|thumb|none|150px|link=http://www.icrp.org/publication.asp?id=ICRP%20Publication%20115|<center>[http://www.icrp.org/publication.asp?id=ICRP%20Publication%20115 ICRP ''Publication 115'' Lung Cancer Risk from Radon and Progeny and Statement on Radon]</center>]]
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<li style="display: inline-block; vertical-align: top;">
[[File:RadonSeeAlso4.jpg|thumb|none|150px|link=http://www.icrp.org/publication.asp?id=ICRP%20Publication%20126|<center>[http://www.icrp.org/publication.asp?id=ICRP%20Publication%20126 ICRP ''Publication'' 126 Radiological Protection against Radon Exposure]</center>]]
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