Your radiation exposure

What are the risks from radiation?

Sources of radiation

Exposure to natural radiation

Exposure to artificial radiation


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 all the way 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.

Sources of radiation

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 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 10-3 of a Sievert and a µSv is 10-6 of a Sievert.

We have published a comprehensive report on Radiation Doses received by the Irish Population.

a chart showing different sources of radiation

Exposure to natural radiation

Learn more about the natural radiation we are exposed to:


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 1995 μSv per year from radon in the home and an additional 229 μSv from radon in the workplace. 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 and on the area you live in. However, you can reduce your exposure to source radon by testing your home for radon and reducing any high levels, if necessary.

Cosmic radiation

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 the altitude we live at. 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 in extremely small. Air crew and airline passengers receive an additional dose from cosmic radiation. The dose received depends on the frequency of flights and the routes flown.

Natural radioactivity in soils

Radioactive elements occur naturally in all rocks and soils and have been there since the creation of the Earth. On average, we receive 295 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 food

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 262 μSv every year from natural radioactivity in food.

Exposure to artificial radiation

The principal sources of man-made or artificial radiation that we are exposed to are:

Medical exposure

Many procedures carried out routinely in medical diagnosis involve exposure to radiation. On average,we receives 546 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:  

  • dental X-ray (10 μSv);
  • chest X-ray (20 μSv);
  • mammography to identify breast cancer (500 μSv);
  • CT scan (5400 μSv);
  • angiocardiogram to determine heart function (6000 μSv).

Artificial radioactivity

On average, we receive 11 μSv every year from artificial radioactivity in the Irish environment. We receive approximately 6 μSv from artificial radioactivity in soils and a further 5 μSv from artificial radioactivity in food. This radioactivity comes from a number of sources, including nuclear weapons testing in the 1950s and 1960s, the in 1986 and discharges from the Sellafield reprocessing plant in the UK.

Working with radiation

If you work with radiation in the medical, industrial or education/research fields, on average you receive a dose of 20 μSv per year. Air crew who fly above 8,000 metres receive an average dose each year of 2326 μSv. If you work with radiation or are air crew, your employer is required by law to keep a record of your doses.

Stringent rules and regulations are in place to protect workers from accidental exposure to harmful levels of radiation. The EPA regulates the use of ionising radiation in Ireland which includes the protection of workers, the . he useall possession and use of irradiating apparatus and radioactive materials to minimise the risks associated with ionising radiation.

Learn More

Estimate your annual radiation dose by using our dose calculator.