Radiation Quality and Effective Dose Equivalent of Alpha Particles from Radon Decay Products Indoors: Uncertainties in Risk Estimation

The radiation dose to patients and personnel was estimated during 11 percutaneous renal stone extractions. For the patients the energy imparted, the mean absorbed dose to various organs, and the effective dose equivalent were estimated. For different personnel categories some organ doses and the effective dose equivalent were also estimated. Large differences in the radiation dose between patients were observed. The mean effective dose equivalent to the patient was 4.2 (range 0.6–8.3) mSv, and the energy imparted 285 (range 50–500) mJ. These figures are comparable to those reported for routine colon examination and urography. For the personnel there were also large differences between individuals and categories. The highest radiation dose was received by the radiologist. It was estimated that a radiologist who performs 150 percutaneous renal stone extractions per year will receive a yearly contribution to his/her effective dose equivalent of 2.4 mSv. Even when the contribution from other diagnostic and interventional radiologic procedures is added, the total effective dose equivalent hardly exceeds 5 mSv or 1/10 of the present dose limit for persons engaged in radiologic work. For the hands of the radiologist there is a risk of doses closer to the present limit for single organs or tissues of 500 mSv/year.

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Current Issues on Effective Dose and Effective Dose Equivalent Used in Radiological Protection.

Japanese Journal of Health Physics ◽

10.5453/jhps.37.245 ◽

2002 ◽

Vol 37 (3) ◽

pp. 245-248

Author(s):

Satoshi IWAI

Keyword(s):

Effective Dose ◽

Radiological Protection ◽

Effective Dose Equivalent ◽

Dose Equivalent

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Evolution of radon dose evaluation

Nuclear Technology and Radiation Protection ◽

10.2298/ntrp0401003f ◽

2004 ◽

Vol 19 (1) ◽

pp. 3-11

Author(s):

Kenzo Fujimoto

Keyword(s):

United Nations ◽

Risk Estimation ◽

Weighting Factor ◽

Historical Change ◽

Radiological Protection ◽

Effective Dose Equivalent ◽

Dose Equivalent ◽

United Nations Scientific Committee ◽

Natural Radiation ◽

Dose Evaluation

The historical change of radon dose evaluation is reviewed based on the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) reports. Since 1955, radon has been recognized as one of the important sources of exposure of the general public. However, it was not really understood that radon is the largest dose contributor until 1977 when a new concept of effective dose equivalent was introduced by International Commission on Radiological Protection. In 1982, the dose concept was also adapted by UNSCEAR and evaluated per caput dose from natural radiation. Many researches have been carried out since then. However, lots of questions have remained open in radon problems, such as the radiation weighting factor of 20 for alpha rays and the large discrepancy of risk estimation among dosimetric and epidemiological approaches.

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