FAQ's on Monitoring and Assessement

Why does the EPA monitor radioactivity in the environment and foodstuffs?

The EPA environmental monitoring programme aims to measure the exposure of the Irish population from radioactivity in the environment, to assess the distribution of radioactivity in the Irish environment and to maintain systems and procedures which would allow a rapid assessment of environmental contamination to be made in the event of a radiological emergency.

How does the EPA decide which samples to take, where to take them and how many to take?

The sample types and radionuclides measured as part of the monitoring programme are reviewed annually by the EPA in order to ensure its stated objectives are achieved. Air, drinking water, foodstuffs, fish, shellfish, seaweed, marine sediment and seawater are sampled at locations around Ireland and tested for radioactivity. In addition, external gamma radiation is measured continuously. These measurements are then used to calculate the dose received by members of the Irish public.

The monitoring programme ensures Ireland’s compliance with the requirements of Article 35 of the EURATOM Treaty. Article 35 requires that levels of radioactivity are measured in all EU Member States to enable the dose to the population as a whole to be calculated. The European Commission has recommended what samples should be taken to fulfil this requirement.

What kind of analysis is done on samples?

A range of analyses are performed depending on the sample type and the radionuclide required to be measured. If possible, samples are analysed by gamma spectrometry; this is a cost-effective technique which can identify a wide range of radionuclides from the characteristic gamma rays they emit.

Not all radioactive elements emit radiation in the form of gamma rays. Therefore, additional techniques are used which fall into two broad categories:

  1. Those that measure a particular type of radiation but do not identify the radioactive elements present, i.e. gross alpha and gross beta, which measure alpha and beta particles respectively
  2. Those that look for specific radioactive elements. These techniques may involve radiochemistry to isolate the radionuclide of interest before measuring the radioactivity.