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Project title

Gamma Radiation Dose Evaluation

Primary Funding Agency

Environmental Protection Agency

Co-Funding Organisation(s)

n/a

Lead Organisation

South East Technological University (SETU)

Lead Applicant

Claire Keary

Project Abstract

External exposure to terrestrial gamma radiation represents a significant component to the total average annual dose received by a person living in Ireland from all sources of ionising radiation. External gamma ray doses from natural radionuclides originate largely from the decay of radionuclides belonging to the radioactive decay series of 238U, 235U and 232Th, as well as from the decay of 40K, all of which have been present on the Earth since its formation. In addition, a number of artificial radionuclides (e.g., 137Cs and 241Am) have been deposited throughout Ireland as a result of fallout from nuclear weapons testing and accidental releases such as those from the Chernobyl and Fukushima nuclear accidents. Since terrestrial gamma radiation depends on the nature of the underlying bedrock and soil composition, as well as the pattern of deposition of artificial radionuclides, an individual’s annual dose as a result of this exposure pathway will largely be determined by their place of residence. Several studies of gamma dose rates from natural and artificial radionuclides in Ireland were conducted in the 1980s and 1990s, and these have formed the basis for the estimation of terrestrial gamma radiation doses in the periodic assessments which are carried out by the EPA on the average annual radiation doses received by the Irish population from all sources of ionising radiation. By undertaking a comprehensive new survey of natural and artificial radionuclide concentrations and gamma ray dose rates throughout Ireland, and linking the results of these ground surveys to the detailed radiometric data generated by the Tellus airborne surveys which have been conducted by the Geological Survey of Ireland since 2012, the GRaDE project aims to develop a better understanding of the geographical distribution of natural and artificial gamma-emitting radionuclide concentrations in the Irish terrestrial environment with a view to providing a more accurate, up to date estimate of the average annual effective dose that a member of the Irish public receives as a result of exposure from terrestrial gamma radiation. By making use of a combination of high-resolution gamma spectrometry measurements, direct gamma dose rates gathered in the field using calibrated field monitors, and the gamma dose rates inferred from available aerial radiometric data on uranium, thorium and potassium concentrations, and 137Cs deposition from the Tellus programme, a set of new, high-resolution maps on radionuclide concentrations and gamma ray dose rates throughout Ireland will be generated using appropriate Geographical Information Systems (GIS) tools. These maps, together with information on population density, will be used to generate a map of outdoor gamma ray doses in Ireland and to investigate the range and average annual doses to a member of the Irish public arising from terrestrial gamma radiation.

Grant Approved

�575,128.00

Research Hub

Healthy Environment

Research Theme

n/a

Start Date

31/03/2024

Initial Projected Completion Date

30/03/2028