What are the risks from radiation?
The effects of and risks from high and very high doses of radiation, including serious injury, cancer and death, are reasonably well known from the scientific study of atomic bomb survivors and accidents.
At lower radiation doses the risk of fatal cancer is not precisely known, but it is assumed that there is a direct relationship between dose and risk to zero (i.e. at zero dose there is zero risk). Here you can find out more about the sources of radiation to which you are exposed to in Ireland and the health risks associated with that exposure.
Watch our short video which summarises the distribution of radiation dose in Ireland.
On average, a person in Ireland receives an annual dose of 4.2 millisieverts (mSv) from all sources of radiation. The sievert is the unit of ‘effective radiation dose’ (dose) and takes into account the biological impact on the human body of ionising radiation. A mSv is 0.001 of a Sievert and a µSv is 0.000001 of a Sievert.
We have published a comprehensive report on Radiation Dose received by the Irish Population.
Most of the natural radioactivity we are exposed to comes from radon gas. Radon is a radioactive gas that comes from rocks and soils in the ground and can seep into buildings such as our homes and workplaces. It can build up to high levels and over time can increase our risk of getting lung cancer. On average, a person receives 2470 μSv per year from radon in the home. We are all exposed to different amounts of radon as the levels of radon vary depending on the area you live in and can vary from house to house. However, you can reduce your exposure to source radon by testing your home for radon and reducing any high levels, if necessary.
Cosmic radiation is high-energy radiation from outer space that reaches the Earth’s surface. The amount of cosmic radiation we are exposed to depends on our current altitude. For example, someone living at sea level receives an average of 302 μSv from cosmic radiation. The dose received varies with latitude and altitude but the variability across Ireland is extremely small. Aircrew and airline passengers receive an additional dose from cosmic radiation. The dose received depends on the frequency of flights and the routes flown.
Radioactive elements occur naturally in all rocks and soils and have been there since the creation of the Earth. In addition, there is a small contribution from artificial radioactivity that is present in soils from the fallout from nuclear weapons testing in the past, nuclear accidents (e.g. Chornobyl) and authorised releases from nuclear facilities abroad. On average, we receive 241 μSv every year from this source.
Thoron, like radon, is a naturally occurring radioactive gas. Unlike radon, its principal source is building materials. On average, a person receives 350 μSv per year from exposure to thoron.
Natural radioactivity in soils is transferred to crops and grazing animals and we are exposed to this radiation in our diet and drinking water. Similarly, the natural radionuclides in the sea are transferred to fish and shellfish. On average, we receive 297 μSv every year from natural radioactivity in food and drinking water.
Many procedures carried out routinely in medical diagnosis involve radiation exposure. On average, we receive 433 μSv per year from medical procedures. Some people receive no dose from medical procedures while others receive much higher doses. Treatments such as radiotherapy result in a dose hundreds of times higher than average. The total dose received depends on the number and type of procedures. Some well-known procedures and the typical doses received are:
Occupational exposures consider the doses incurred by people as a result of their work. These include, for example: aircrew who are exposed to higher levels of Cosmic radiation and people who may potentially be exposed to artificial sources of radiation in the fields of medicine, industry and education/research.
The estimated annual dose from occupational exposure is 11.5 μSv and is dominated by the doses received by aircrew.
Stringent rules and regulations are in place to protect workers from accidental exposure to harmful levels of radiation. The EPA is responsible for the protection of the public and workers from the harmful effects of natural and artificial radiation.
Responsibility for the protection of patients during the use of radiation in medical procedures rests with the Health Information and Quality Authority (HIQA).
Estimate your annual radiation dose by using our dose calculator.
