On average, a person living in Ireland receives a dose of 4.2 millisieverts (mSv) per year from all sources of radiation. The results of your calculation can vary quite widely from the average calculated for the population as a whole.
Described below is an explanation of each of the components of your radiation dose. You may wish to put your dose into perspective by looking at the health-risk associated with various radiation doses. We have published a comprehensive report on the Radiation Doses Received by the Irish Population.
Radon is a radioactive gas that occurs naturally in the ground and when it enters a building it can build up to unacceptable levels. For most people, radon is the major contributor to their total dose. Approximately 60% of the average radiation dose (2.47 mSv) is due to exposure to radon in indoor air. However, exposure to radon for the individual is extremely variable - ranging from a fraction to hundreds of times the average radiation dose.
This source of radiation exposure, among all others, is probably the easiest to reduce. We strongly recommend that you measure the level of radon in your home and reduce it if it is above the acceptable level.
The public receives a radiation dose from cosmic radiation (high-energy radiation from outer space reaching the Earth’s surface) both on the ground (0.302 mSv) and while flying (0.068 mSv). The dose received by aircrew and airline passengers due to air travel depends on the frequency of flights and the route taken.
Occupational exposures can arise from natural and human-made sources of radiation. Occupational exposure of aircrew to cosmic radiation is reported annually by the airlines to the EPA. This dose assessment includes aircrew data up to 2019 (the years 2020 – 2022 are excluded due to the COVID pandemic). The radiation dose to aircrew is estimated to be 0.0115 mSv. There is also a small contribution to the overall radiation dose due to occupational exposures in the workplace to people working .
Many procedures carried out routinely in medical diagnosis involve radiation exposure. On average, a person receives 0.43 mSv per year from medical procedures. This average value does not include doses from medical treatment such as radiotherapy, which can often be several hundred times higher.
Some people receive no dose from medical procedures while others receive much higher doses. The total dose received depends on the number and type of procedures. Some well-known procedures and the typical doses received are general X-ray (0.063mSv); Fluoroscopy and Fluoroscopically Guided Interventions (0.051 mSv); Positron Emission Tomography (PET) (0.032 mSv); CT scan (0.27 mSv), Diagnostic Nuclear Medicine (0.016 mSv) and dental X-rays (0.001 mSv).
All medical exposures to radiation must be clinically justified and should only be carried out if recommended by a GP or medical consultant.
On average, a person receives 0.350 mSv per year from exposure to thoron. Thoron, like radon, is a naturally occurring radioactive gas. Unlike radon, its principal source is building materials.
The estimated annual dose from gamma radiation in the ground is 0.241 mSv. The main sources of exposure from natural radioactivity on the ground is gamma radiation from potassium-40 (K-40), uranium-238 (U-238) and thorium-232 (Th-232). In addition, there is a small contribution from artificial radioactivity present in Irish soils. Artificial radiation includes radiation from fallout from nuclear weapons testing in the past, nuclear accidents (for example, Chornobyl), and authorized releases from nuclear facilities abroad.
The radiation dose from food and drinking water is estimated to be 0.296 mSv that is comprised of 0.292 mSv from natural radiation and 0.004 mSv from artificial sources.