Task Group 111
Factors Governing the Individual Response of Humans to Ionising Radiation

A Taskgroup under Committee 1 and Committee 3

Tissue reactions and stochastic effects after exposure to ionising radiation are variable between individuals. Factors and mechanisms governing individual responses to ionising radiation are complex and not well understood. These responses can be measured at different levels of biological organization following varying doses of radiation by analysing different endpoints such as cancers, non-cancer diseases and mortality in the whole organism; normal tissue reactions after exposures; and cellular endpoints such as chromosomal damage and molecular alterations. There are many factors that, to different degrees, influence the responses of individual people to radiation. In addition to the obvious factors of radiation quality, dose, dose rate and the tissue (sub)volume irradiated, determining factors include, among others, age and sex, life style (e.g. smoking, diet, and possibly body mass index), environmental factors, genetics and epigenetics, stochastic distribution of cellular events and systemic comorbidities such as diabetes or viral infections. Genetic factors are commonly thought to be a substantial contributor to individual response to radiation. The inheritance of an abnormally responsive phenotype among a population of healthy individuals does not follow a classical Mendelian, monogenic heredity pattern. Rather it is considered to be a multi-factorial, complex trait. The Task Group will develop a report for publication in the Annals of the ICRP that presents a review of the current science relevant to the topic of individual response to radiation.

Simon Bouffler (Chair), PHE, UK
Michel Bourguignon (Member), French Institute for Radiological Protection and Nuclear Safety (IRSN), France
Michael Hauptmann (Member), Netherlands Cancer Institute, Netherlands
Claudia E. Ruebe (Member), Saarland University, Germany
Andrzej Wojcik (Member), Centre for Radiation Protection Research, Stockholm University, Sweden