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| {{Header}}
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| ==Introduction==
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| [[File:Radiation warning symbol.jpg|thumb|Radiation warning Symbol]]
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| This page introduces the possible effects of radiation on development. The two main sources of exposure are environmental and those used for medical diagnostic or therapeutic purposes. The teratogenic effects of radiation were identified by Gilman Baetjer (1906)<ref name=GilmanBaetjer1906>{{ref-GilmanBaetjer1906}}</ref>
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| and later by Bagg (1922).<ref name=Bagg1922>{{Ref-Bagg1922}}</ref>
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| <center>''Radiation - electromagnetic waves or quanta, and atomic or sub-atomic particles, propagated through space or through a material medium.''</center>
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| Studies have shown that in maternal X-ray diagnostic examination, where the beam does not irradiate the embryo/fetus directly (maternal skull and chest X-ray), the absorbed dose for the embryo or fetus is extremely low (less than 0.01 mGy). Treatment of hyperthyroidism with 131 Iodine in a pregnant woman is strictly contraindicated due to the effects on the developing embryonic thyroid gland.
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| {{Environmental}}
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| {| class="wikitable mw-collapsible mw-collapsed"
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| ! [[Embryology_History|Historic Radiation]]
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| | [[Paper - Some effects of the Röntgen rays on the development of embryos|1904 X-Rays]] | [[Paper - Disturbances in mammalian development produced by radium emanation|1922 Radium Effects]]
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| [[File:Proposed radiation effect classification.jpg|thumb|Proposed radiation effect classification{{#pmid:24794798|PMID24794798}}]]
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| ==Some Recent Findings==
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| * '''Japan - Nationwide Increase in Cryptorchidism after the Fukushima Nuclear Accident'''{{#pmid:29751027|PMID29751027}} "To estimate the change of discharge rate after cryptorchidism surgery between pre- and post-disaster in Japan. The change in discharge rate between pre- and post-disaster was analysed using a Bayesian Generalized Linear Mixed Model (GLMM). Nationwide, a 13.4 % (95% credible interval 4.7-23.0 %) increase in discharge rates was estimated. The results of all sensitivity analyses were similar to the reported main results. The discharge rate of cryptorchidism was increased nationwide. The rates of low-weight babies or preterm births, risk factors of cryptorchidism, were almost constant during the study period, and age distribution of the surgery was also not changed, which suggested that the other factors that associated with the disaster increased the incidence of cryptorchidism." [[Japan Statistics]] | {{genital abnormalities}}
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| * '''Risk of death among children of atomic bomb survivors after 62 years of follow-up: a cohort study'''{{#pmid:26384241|PMID26384241}} "No clear epidemiological hereditary effects of radiation exposure in human beings have been reported. However, no previous studies have investigated mortality into middle age in a population whose parents were exposed to substantial amounts of radiation before conception. We assessed mortality in children of the atomic bomb survivors after 62 years of follow-up. ...Late effects of ionising radiation exposure include increased mortality risks, and models of the transgenerational effects of radiation exposure predict more genetic disease in the children of people exposed to radiation. However, children of people exposed to the atomic bombs in Hiroshima and Nagasaki had no indications of deleterious health effects after 62 years. Epidemiological studies complemented by sensitive molecular techniques are needed to understand the overall effects of preconception exposure to ionising radiation on human beings."
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| * '''Overview of International Commission on Radiological Protection Committee 1: radiation effects'''{{#pmid:26635336|PMID26635336}} "This paper does not necessarily reflect the views of the International Commission on Radiological Protection. The author passed away on 13 November 2015.Committee 1 of the International Commission on Radiological Protection (ICRP) addresses issues pertinent to tissue reactions, risks of cancer and heritable diseases, radiation dose responses, effects of dose rate, and radiation quality. In addition, it reviews data on the effects of radiation on the embryo/fetus, genetic factors in radiation response, and uncertainties in providing judgements on radiation-induced health effects. Committee 1 advises the Main Commission on the biological basis of radiation-induced health effects, and how epidemiological, experimental, and theoretical data can be combined to make quantitative judgements on health risks to humans. The emphasis is on low radiation doses, in the form of detriment-adjusted nominal risk coefficients, where there are considerable uncertainties in terms of the biology and the epidemiology."
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| * '''Malformations in a chornobyl-impacted region'''{{#pmid:20308207|PMID20308207}} "The overall rate of neural tube defects in Rivne is among the highest in Europe (22.2 per 10,000 live births). The rates of conjoined twins and teratomas also seem to be elevated. In Polissia, the overall rates of neural tube defects are even higher (27.0 vs 18.3, respectively; odds ratio: 1.46 [95% confidence interval: 1.13-1.93]), and the rates of microcephaly and microphthalmia may also be elevated."
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| * '''Recently revised diagnostic reference levels in nuclear medicine in Bulgaria and in Finland.'''{{#pmid:20142277|PMID20142277}} "An EU twinning project entitled 'Strengthening of administrative structures for radiation protection and safe use of ionising radiation in diagnostics and therapy' was established between Bulgaria and Finland, lasting from June 2008 to May 2009."
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| {| class="wikitable mw-collapsible mw-collapsed"
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| ! More recent papers
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| | [[File:Mark_Hill.jpg|90px|left]] {{Most_Recent_Refs}}
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| Search term: [http://www.ncbi.nlm.nih.gov/pubmed/?term=Radiation+Effects ''Radiation Effects'']
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| <pubmed limit=5>Radiation Effects</pubmed>
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| ==Diagnostic Radiography==
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| [[File:Renal agenesis 01.jpg|thumb|X-ray diagnosis of renal agenesis]]
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| A recent Australian review study has shown minimal effects of standard diagnostic radiography underspecific conditions.<ref><pubmed>15191441</pubmed></ref>
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| :"The only adverse effect statistically proven at the dose levels associated with diagnostic radiation procedures is a very small increase in childhood malignancy, with an estimated increase of one additional cancer death per 1700 10 mGy exposures. The important exception was the risk to the fetal thyroid from radioiodine exposure after 12 weeks' gestation."
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| == Dual X-ray Absorptiometry ==
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| These types of radiological studies can be carried out in osteoporosis examinations.
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| "The aim of the current study was to estimate the embryo/fetus radiation doses and risks associated with spinal and hip dual X-ray absorptiometry (DXA) scans performed on the pregnant mother."
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| "In conclusion, the embryo/fetus dose in bone density measurements of spine and femur using pencil beam DXA is lower than the average daily natural background in the United States of 8 mGy. The health provider can decide whether a DXA scanning is beneficial to a pregnant woman, taking into account the potential radiation risks to the embryo/fetus presented in the current study."
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| [http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12195535 Damilakis J, Perisinakis K, Vrahoriti H, Kontakis G, Varveris H, Gourtsoyiannis N.] Embryo/fetus radiation dose and risk from dual X-ray absorptiometry examinations. Osteoporos Int. 2002 Sep;13(9):716-22.
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| ==Computed Tomography==
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| [[File:Micro-computed tomography apparatus.jpg|thumb|Research Micro-computed tomography apparatus]]
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| Computed Tomography or computed axial tomography (CAT or CT scan) began in 1970's using x-ray and a computer to produce images either as individual slices or reconstructed to give three dimensional (3D) views of specific anatomical regions or structures. While some standard x-ray examinations of the abdomen may not pose a serious risk, some abdominal and pelvic CT studies deliver greater amounts of radiation to a developing pregnancy.
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| :'''Links:''' [[Computed Tomography]]
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| == International Commission on Radiological Protection ==
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| "Almost always, if a diagnostic radiology examination is medically indicated, the risk to the mother of not doing the procedure is greater than is the risk of potential harm to the fetus. Most nuclear medicine procedures do not cause large fetal doses. However, some radiopharmaceuticals that are used in nuclear medicine can pose significant fetal risks. It is important to ascertain whether a female patient is pregnant prior to radiotherapy."
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| "...Fetal doses below 100 mGy should not be considered a reason for terminating a pregnancy."
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| [http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11108925 International Commission on Radiological Protection] Pregnancy and medical radiation. Ann ICRP. 2000;30(1):iii-viii, 1-43.
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| "It should be also remembered that irradiation of the fetus in all trimesters of the pregnancy carries an increased risk of cancer in the newborn in the first or second decade of life and at therapeutic doses - or their significant fraction - this risk can be substantial. Therefore, in view of all mentioned factors termination of pregnancy may be considered. The decision should be based on careful estimation of the entailed risk to the fetus, which in turn requires calculation of the dose to conceptus by a qualified expert. The decision itself should be made by the women to be treated in consultation with their physician, partner and counsellor. Particularly difficult problems arise when radiotherapy is performed in a woman with early, undiagnosed pregnancy. The result is sometimes a massive irradiation of the conceptus in a period when malformations are easily induced (at or after 3 weeks post conception).
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| To avoid such unintentional irradiation it seems necessary to perform pregnancy tests to diagnose, or exclude the pregnancy before undertaking radiotherapy.
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| Therapy of hyperthyroidism with 131 Iodine in a pregnant woman is strictly contraindicated due to possibility of external irradiation of the foetus but mostly due to radioactive iodide crossing the placenta into the foetal circulation with subsequent uptake by its thyroid. The gland may well be destroyed by beta radiation from the nuclide taken up (131I). Therefore, other methods of treatment should be employed, if possible, until delivery." (Text extract from: [http://www.icrp.org/docs/Rad_for_GP_for_web.pdf ICRP Radiation and your Patient: A Guide for Medical Practitioners] PDF document (17 pages, 142 kB)
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| '''Links:''' [http://www.icrp.org/ International Commission on Radiological Protection] | [http://www.icrp.org/downloadDoc.asp?document=docs/ICRP_84_Pregnancy_s.pps Pregnancy and Pedical Radiation] Powerpoint Slide set(1.3 Mb) | [http://www.icrp.org/docs/Rad_for_GP_for_web.pdf Radiation and your Patient: A Guide for Medical Practitioners] PDF document (17 pages, 142 kB) |
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| ==Australia==
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| Australia has a National Standard for Limiting Occupational Exposure to Ionising Radiation (1995, Republished March 2002). Published by the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) to promote practices which protect human health and the environment from the possible harmful effects of radiation. ARPANSA is assisted in this task by its Radiation Health and Safety Advisory Council, which reviews the publication program for the Series and endorses documents for publication, and by its Radiation Health Committee, which oversees the preparation of draft documents and recommends publication.
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| {| | | {| |
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| | ! Radiation Terms |
| ! colspan=2|Australian Occupational Radiation Dose Limits | |
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| | Effective dose limit<sup>1</sup> | | | (based on Australian Standard - NOHSC:3022) |
| | 20 mSv per year, averaged over a period of 5 consecutive calendar years
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| | Effective dose limit in a single year<sup>1</sup>
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| | 50 mSv
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| | Equivalent dose limit - lens of the eye | | | |
| | 150 mSv per year
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| | Equivalent dose limit - skin
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| | 500 mSv per year
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| | Equivalent dose limit - hands and feet
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| | 500 mSv per year
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| | colspan=2|1. The limits shall apply to the sum of the relevant doses from external exposure in the specified period and the 50-year committed dose from intakes in the same period.
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| | colspan=2|Based on Australian NOHSC1013 1995
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| |}
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| :'''Links:''' [http://www.safeworkaustralia.gov.au/sites/SWA/about/Publications/Documents/565/NatioanlStandardLimitingOccupationalExposureIonisingRadiationNOHSC1013_1995.pdf Standard - NOHSC:3022 PDF] | [http://www.safeworkaustralia.gov.au/sites/swa/about/publications/pages/nohsc1013_1995 Safework Australia]
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| ==References==
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| <references/>
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| ===Reviews===
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| {{#pmid:27527732}}
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| {{#pmid:26116850}}
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| {{#pmid:24794798}}
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| {{#pmid:17963274}}
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| ==Terms==
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| {{Radiation terms}}
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| (based on Australian Standard - NOHSC:3022)
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| * '''Absorbed dose ''' - the energy absorbed per unit mass by matter from ionizing radiation which impinges upon it. | | * '''Absorbed dose ''' - the energy absorbed per unit mass by matter from ionizing radiation which impinges upon it. |
| * '''Accident ''' - an unintended event which causes, or has the potential to cause, employees or members of the public to be exposed to radiation from which the individual doses or collective doses received do not lie within the range of variation which is acceptable for normal operation. An accident may result from human error, equipment failure or other mishap; it may require emergency action to save life or to safeguard health, property or the environment; it requires investigation of its causes and consequences and, possibly, corrective action within the program for control of radiation; and it may require remedial action to mitigate its consequences. | | * '''Accident ''' - an unintended event which causes, or has the potential to cause, employees or members of the public to be exposed to radiation from which the individual doses or collective doses received do not lie within the range of variation which is acceptable for normal operation. An accident may result from human error, equipment failure or other mishap; it may require emergency action to save life or to safeguard health, property or the environment; it requires investigation of its causes and consequences and, possibly, corrective action within the program for control of radiation; and it may require remedial action to mitigate its consequences. |
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| * '''Tissue weighting factor ''' - a factor which modifies equivalent dose in an organ or tissue to yield effective dose and which is the partial contribution from the organ or tissue to the total detriment resulting from uniform irradiation of the whole body. | | * '''Tissue weighting factor ''' - a factor which modifies equivalent dose in an organ or tissue to yield effective dose and which is the partial contribution from the organ or tissue to the total detriment resulting from uniform irradiation of the whole body. |
| * '''X-ray''' - ionizing electromagnetic radiation emitted during the transition of an atomic electron to a lower energy state or during the rapid deceleration of a charged particle. | | * '''X-ray''' - ionizing electromagnetic radiation emitted during the transition of an atomic electron to a lower energy state or during the rapid deceleration of a charged particle. |
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