Update on RPII radioactivity monitoring results following Fukushima accident in Japan

Date released: Apr 06 2011

Trace levels found far below those of concern to public health.

The Radiological Protection Institute of Ireland (RPII) has detected trace amounts of radioactivity in further samples following the Fukushima accident in Japan. The levels measured are very low and far below levels which might be of concern to public health.

Dr Ann McGarry, Chief Executive of the RPII said: “In response to the ongoing situation in Japan, we increased the frequency with which we monitor air, rainwater and milk. Levels of radioactivity detected in air have fluctuated, but most recent measurements suggest a trend of decreasing levels over the last couple of days.”

Samples of air collected over 48 hour periods covering 28th March/30th March; 30th March/1st April; 1st/3rd April and 3rd/5th April showed levels of 550, 1000, 229 and 442 micro-becquerels per cubic metre of air of radio-iodine (Iodine-131), respectively. These levels are consistent with the known pattern of release from Fukushima, with findings in other countries and with earlier measurements made by RPII. If a person was to breathe these levels of radioactivity for a period of a whole year they would receive a radiation dose of less than 0.03 micro-sieverts. This radiation dose can be compared with the dose of 4,000 micro-sieverts received on average by people in Ireland each year from natural and man-made sources of radiation.

A sample of rainwater collected in Dublin over the period 22 March/4th April showed levels of 2.6 becquerels per litre of iodine-131. This level is of no concern from a public health perspective.

In response to the Fukushima accident, the frequency of milk sampling was increased. Samples of milk collected on April 2nd, 3rd and 4th showed levels of 0.13, 0.19 and 0.18 becquerels per litre of iodine-131, respectively. The highest of these values is 2600 times lower than the level at which any action would need to be considered. These levels pose no risk to public health. 

“These findings are of no health significance and are comparable with those detected in other parts of Europe.” concluded Dr McGarry.

For further information: 

Murray Consultants 01 498 0346 

Aoibheann O’Sullivan 087 629 14 53

Radiological Protection Institute of Ireland 269 7766

David Dawson 206 6913

Notes for editors: 

Radiological Protection Institute of Ireland (RPII)

The Radiological Protection Institute of Ireland (RPII) is the national organisation with regulatory, monitoring and advisory responsibilities in matters relating to ionising radiation. In particular, the RPII concerns itself with hazards to health associated with ionising radiation and with radioactive contamination in the environment.

The RPII is an independent public body under the aegis of the Department of Environment, Heritage and Local Government and was established in 1992 under the Radiological Protection Act, 1991. The RPII’s role is to ensure that Irish people and the environment are adequately protected from the harmful effects of ionising radiation. We do this by providing advice to the public and the Government, by monitoring people’s exposure to radiation, by regulating and licensing those who use radiation, by providing technical support to Ireland’s plan to deal with radiation emergencies (NEPNA) and by cooperating with similar bodies internationally.


Is the period of time it takes for a substance undergoing radioactive decay to decrease by half. That is, after one half life, 50 per cent remains, after two half lives 25 per cent remains and so on.

RPII’s Environmental monitoring programme

The RPII carries out rigorous and continuous testing to ensure that environmental radiation remains within internationally agreed and legal safety limits. These tests ensure that we are quickly aware of any change in environmental radiation in Ireland, and able to provide any necessary advice to the public and Government.

The key elements of the RPII monitoring programme are:

  • Assessment of ambient radioactivity based on measurements of radioactivity in air and of external gamma dose rate from a network of permanent monitoring stations located throughout the country.
  • Assessment of levels of radioactivity in a variety of food products and drinking water
  • Assessment of levels of radioactivity in the Irish marine environment based on sampling and measurement of seawater, sediment, seaweed, fish and shellfish

The programme combines round-the-clock measurements from the permanent monitoring network and a programme of sampling followed by laboratory testing.

Results from the environmental monitoring in response to the Fukushima accident