ICRP-118-2011) Published new version decreased dose limit for occupational workers from 150 mSv to 20 mSv but i did not find any publication concerning any change in eye lens dose limit for public.
My understanding is that the lens limit for students and apprentices (16-18 years) and members of the public is 15 mSv per year. The paper by Barnard et al mentions this (Br J Radiol 2016; 89: 20151034) although the main focus is on occupational limits.
The ICRP, in April 2011, issued a statement on tissue reactions in which it recommended for occupational exposure a dose limit for equivalent dose to the lens of the eye of 20 mSv in a year, averaged over defined periods of 5 years, with the dose in no single year exceeding 50 mSv [1]. Previously, this dose limit had been 150 mSv per year [2]. The dose limit for lens in case of public exposure was not changed. In terms of equivalent dose to the lens of the eye, it is of 15 mSv in a year. The IAEA implemented those recommendations into the General Safety Requirements Part 3 [3].
[1] ICRP Statement on Tissue Reactions / Early and Late Effects of Radiation in Normal Tissues and Organs – Threshold Doses for Tissue Reactions in a Radiation Protection Context. ICRP Publication 118, Ann ICRP Vol 41 No 1-2, 2012.
[2] The 2007 Recommendations of the International Commission on Radiological Protection. ICRP Publication 103, Ann ICRP Vol. 37 No. 2-4, 2007.
[3] Radiation Protection and Safety of Radiation Sources: International Basic Safety Standards. General Safety Requirements Part 3, Safety Standard Series No. GSR Part 3, IAEA, Vienna (2014)
http://www-pub.iaea.org/books/iaeabooks/8930/Radiation-Protection-and-Safety-of-Radiation-Sources-International-Basic-Safety-Standards
To the best of my knowledge, ICRP Publication 118 did not specify a dose limit for the lens of the eye for the public. However, the 2014 edition of the IAEA Basic Safety Standards (General Safety Requirements Part 3) specifies a dose limit of 20 mSv/y for occupational exposure of students and apprentices 16 -18 years of age, and a public exposure dose limit of 15 mSv/y (Schedule 3, pp. 132-133). (Logically, since radiation effects on the lens of the eye are a tissue reaction, the limits should be expressed in Gy, not Sv.)
Highest thank for your documented answers
the occupational exposure a dose limit for equivalent dose to the lens of the eye of 20 mSv in a year, averaged over defined periods of 5 years, with the dose in no single year exceeding 50 mSv ( ICRP-118-2011)
the public exposure a dose limit for equivalent dose to the lens of the eye, 15 mSv in a year.( IAEA BASIC SAFETY STANDARD, 2014.)
Donald, that's a good point about the dose limit being in Sieverts. The overall dose limits are in effective dose then you've got skin, extremities and eye limits in equivalent dose, all with the same unit. It's a recipe for confusion. As far as I'm concerned, whenever you're dealing with partial organ doses such as a portion of skin, you should use Gray, regardless of whether dealing with tissue reactions or stochastic effects.
Dear Richard, sorry, but we cannot use Sieverts or Grays in expression of dose levels. Mr. Sievert and Mr. Gay dead many years ago, as I know. The same about Mr. Becquerel – he also dead. For name of dose quantity one shall use sievert, but Sv; gray, but Gy; or becquerel, but Bq. For reference, please, take a look on the glossary in ICRP-103 or GSR Part 3.
Richard, I agree the units are very confusing, see the questions and answers for
What is the difference between Sievert and Gray? A practical question concerning the SI units for ionizing radiation.
One should not make an arbitrary decision for when to use sievert or gray. We need to fix the problem created by ICRP nomenclature.
Vladimir, note that I misspelled the units with capitals in the above question. I will stop doing that. I did know better.
Look this site: http://www.icrp.org/docs/Miroslav%20Pinak%20Dose%20Limits%20to%20the%20Lens%20of%20the%20Eyes%20New%20Limit%20for%20the%20Lens%20of%20the%20Eye%20-%20International%20Basic%20Safety%20Standards%20and%20Related%20Guidance.pdf
The unit of both the effective and equivalent dose is Sv. As long as the use of Radiation weighting factor (wR) is implied, the unit has to be Sv for the equivalent dose also. For Gy to be used for Tissue reactions (at doses much higher than the dose limits, especially in accident situations), the wR values are not to be used. Instead, if the high LET particles (e.g., neutron or alpha particle) are involved, the dose for tissue reaction is weighted by an RBE(dependent on energy, dose and dose rate) factor to arrive at RBE-weighted dose, RBE-D (Gy).
The recent models for assessment consequences of radiation exposure of humans define the system of dosimetric quantities. The IAEA publication on emergency preparedness and response (EPR) define areas of their applicability in details. The EPR deals with full spectrum of health effects from undetectable to severe deterministic as given in [1, 2, 3, 4, 5, 6]. All those publications in different UN Languages are available at http://www-pub.iaea.org/books/ . Unfortunately, because of position of the ICRP and ICRU [5], the only two names for dose units could be used for those quantities: sievert (Sv) and gray (Gy) as follows.
Sv is used as a name for unit of equivalent dose in organ or tissue; effective dose; personal, ambient and directional dose equivalent, etc.
Gy is used for adsorbed dose in in organ or tissue; RBE-weighted dose in organ or tissue, etc.
That situation is a source for errors and misunderstanding. To avoid them, in expression of dosimetric information, one must use notation to the dosimetric quantity, not only of unit. For instance, in case of internal intake of some certain amount of I-131, the human exposure could be expressed as following
100 mGy of absorbed dose in thyroid;
100 mSv of equivalent dose in thyroid;
5 mSv of effective dose; and
20 mGy of RBE-weighted dose in thyroid.
___________________________
[1] Extended Framework of Emergency Response Criteria: Interim Report for Comments, IAEA-TECDOC-1432, IAEA, Vienna (2005)
[2] Generic procedures for medical response during a nuclear or radiological emergency, Emergency Preparedness and Response Series EPR-MEDICAL, IAEA, Vienna (2005).
[3] Dangerous Quantities of Radioactive Material, Emergency Preparedness and Response Series EPR-D-VALUES, IAEA, Vienna (2006).
[4] Criteria for Use in Preparedness and Response for a Nuclear or Radiological Emergency, IAEA Safety Standards Series No. GSG-2, IAEA, Vienna (2011).
[5] Radiation Protection and Safety of Radiation Sources: International Basic Safety Standards. General Safety Requirements Part 3, Safety Standard Series No. GSR Part 3, IAEA, Vienna (2014).
[6] Preparedness and Response for a Nuclear or Radiological Emergency. General Safety Requirements Part 7, Safety Standard Series No. GSR Part 7, IAEA, Vienna (2015).
In April 2011 (immediately after its Main Commision meeting held in Seoul, South Korea), ICRP released "Statement on Tissue Reactions", which later became part of ICRP Publication 118 issued in August 2012. As already mentioned by other experts, IN this so called "Seoul Statement", ICRP recommended reducing the occupational dose limit from 150 mSv/year to 100 mSv/5 year and
For your information, NCRP (US National Council on Radiation Protection and Measurements) has just published Commentary No. 26 "Guidance on radiation dose limits for the lens of the eye", which was prepared by its Program Area Committee 1/Scientific Committee 1-23 (NCRP/PAC1/SC 1-23). https://www.researchgate.net/publication/312088649_Guidance_on_radiation_dose_limits_for_the_lens_of_the_eye
With this Commentary, NCRP now recommends reducing an occupational dose limit for the ocular lens from equivalent dose of 150 mSv/year to absorbed dose of 50 mGy/year along with the use of the relative biological effectiveness (RBE) for high linear energy transfer (LET) radiation.
Provided below are four key questions addressed in this Commentary.
[1] Should radiation-induced cataracts be characterized as stochastic effects or tissue reactions?
[2] What effects do linear-energy transfer (LET), dose rate, acute and/or protracted dose delivery have on radiation cataract induction and progression?
[3] How should detriment be measured and/or evaluated for radiation cataracts?
[4] Based on current evidence, should NCRP change the recommended annual occupational equivalent dose limit for the lens of the eye?
Article Status of NCRP Scientific Committee 1-23 Commentary on Guida...
Article Guidance on radiation dose limits for the lens of the eye
On annual dose limit for student and apprentice in the course of their studies, who are obliged to use sources ,that there dose limit shall be the same as the dose limits for exposed workers. WHO is please responsible for the monitoring? Is it applicable also to student undergoing clinical experience/training at a Radiology facility? Thanks
My responses to Prof/Dr/Mr Mathew Abubakar are provided below.
The International Commission on Radiological Protection (ICRP) issued a statement on 21 April 2011 that recommended reducing the occupational equivalent dose limit for the lens of the eye from 150 mSv/year to 20 mSv/year averaged over five years with no year exceeding 50 mSv/year. ICRP defines worker as "any person who is employed, whether full time, part time or temporarily, by an employer, and who has recognized rights and duties in relation to occupational radiological protection", according to ICRP Publication 103. Adult workers are those at age 18-64 years.
The International Atomic Energy Agency (IAEA) decided on 12 July 2011 to implement such ICRP’s new lens dose limit. In its latest BSS (Basic Safety Standards called GSR Part 3, its interim issued in 2011 and final version in 2014), for occupational exposure of workers over age 18 years, the dose limit is as what ICRP recommended. For occupational exposure of apprentices of 16 to 18 years of age who are being trained for employment involving radiation and for exposure of students of age 16 to 18 who use sources in the course of their studies, the dose limit is 20 mSv/year (i.e., with no single year exceeding 20 mSv/year).
Situations should be different among countries each with different national regulation and policy, but all people who enter radiation control area (regardless of whether routinely or occasionally) should wear dosimeter.
@Abubakar: For trainees the dose limits are 1/3 of the dose limits for occupational workers in India. These are specified by National Regulatory Authorities. The number may vary from country to country but the dose limits for students/Trainees (>16 years) are generally lower than that of occupational radiation workers.
The aforementioned ICRP’s revised occupational equivalent dose limit for the lens has begun to be implemented into the national regulation. EU Member States will implement it by 6 February 2018. Japan (Radiation Council) decided in June 2017 to implement it, but has not yet decided when to implement it. US (Nuclear Regulatory Commission) won’t change the limit, although NCRP (National Council on Radiation Protection and Measurements) recommended reducing 150 mSv/year to 50 mGy/year along with the use of the RBE (relative biological effectiveness) for high linear energy transfer radiation.
What is the current situation in India, Dr Munish Kumar?
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