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Task Group 90
Age-dependent Dose Conversion Coefficients for External Exposures to Environmental Sources

External exposure to environmental sources is an important pathway of exposure of the public after major releases of radionuclides to the environment. In the early stage after a nuclear accident, internal exposures due to inhalation and ingestion of radionuclides are likely to significantly contribute to organ doses and effective dose. However, some time after an accidental release external exposure is a major contributor to the doses of members of the public. This is also the case after the accident at the nuclear power plant (NPP) in Fukushima Prefecture, Japan in March 2011. Age-dependent dose coefficients for the internal exposures have been evaluated comprehensively by ICRP (Publications 56, 67, 69, 71, 72 currently under revision), while age-dependent dose conversion coefficients for external exposures have not been evaluated by ICRP. The purpose of the proposed report is, therefore, to provide age-dependent dose conversion coefficients for external environmental exposures.

Conversion coefficients are needed to evaluate effective dose from measurements of air kerma, the absorbed dose in air, or the ambient dose equivalent. Calculation of the conversion coefficients requires the evaluation of the environmental field (i.e. density and composition of soil, radionuclide distribution), the model of the human body, i.e. the phantoms that represent the members of the public, and the simulation of the radiation transport. Organ doses depend on body mass since, in external photon exposure, increasing amounts of overlying tissue enhances the shielding of the organs located beneath the subcutaneous adipose mass. Therefore, reference models of adults as well as of children of different ages will be used in the calculations.

Conversion coefficients for environmental exposures will be computed for the ICRP voxel-based adult male and female reference computational phantoms (ICRP Publication 110) as well as for the 10 pediatric NURB-based phantoms of the University of Florida. The latter have been selected to become the reference ICRP pediatric phantoms. The Task Group (TG) will identify the most probable exposure scenarios for the simulation (see outline of the task). The TG will have close collaboration with DOCAL.

Symposium on Radiological Protection Dosimetry 18 Feb 2016


Dr Nina Petoussi-Henss 
Helmholtz Zentrum München, Germany

Business Address
Helmholtz Zentrum München
German Research Center for Environmental Health
Department of Medical Radiation Physics and Diagnostics
Ingolstaedter Landstr. 1
85764 Neuherberg

Telephone and E-mail
49 89 3187 2791 (Office)
49 89 3187 2517 (Fax) (Office)


Prof Wesley E. Bolch 
University of Florida, USA
Curriculum Vitae

Business Address
Advanced Laboratory for Radiation Dosimetry Studies (ALRADS)
Department of Biomedical Engineering
1275 Center Drive
University of Florida
Gainesville 32611-6131

Telephone and E-mail
352 273 0303 (Office) (Main email) (Office)
9501 SW 56th Place
Gainesville, Florida 32608
Dr Keith Eckerman 
Oak Ridge National Laboratory (ORNL), USA
Dr Akira Endo 
Japan Atomic Energy Agency (JAEA), Japan
Dr Helmut Schlattl 
Helmholtz Zentrum München , Germany

Corresponding Members

Michael Bellamy 
Oak Ridge National Laboratory, USA

Telephone and E-mail (Office)
Daiki Satoh, Ph. D. 
Japan Atomic Engergy Agency, Japan

Telephone and E-mail (Main email)
Prof Nolan E Hertel 
Georgia Institute of Technology, USA
Curriculum Vitae

Telephone and E-mail (Main email)
Dr John G S Hunt 
The Instituto de Radioproteção e Dosimetria, Brazil
Dr. Jan T.M. Jansen 
Public Health England, UK
Dr Choonsik Lee 
National Cancer Institute, USA
Curriculum Vitae

Business Address
9609 Medical Center Dr. 7E-448
Rockville, MD 20850

Telephone and E-mail
1 240 276 7374 (Office) (Main email) (Office)
Dr Kimiaki Saito 
Japan Atomic Engergy Agency, Japan

Telephone and E-mail (Main email)
Yeon Soo Yeom 
Hanyang University, Korea
Dr Song Jae Yoo 
Korea Institute of Nuclear Safety(KINS), Korea