Radiation dose from artificial radioactive substances, 1960-2000
Changes in radiation dose
The fall-out from nuclear test sites, particularly from the 1961-1962 period, and the nuclides spread following the Chernobyl reactor accident in 1986, continue to make the biggest contribution (approximately 11 µSv in 2000) to the annual average dose per capita from artificial radionuclides in the environment. By comparison, the contribution to the average dose from standard discharges from, for example, nuclear power plants, hospitals and research laboratories, which amount in total to of 1 µSv (rounded off) per year, can be seen as negligible. The dose from artificial sources in the environment amounts to less than 1% of the total radiation load.
Policy
A major proportion of the dose received by people as a result of artificial radionuclides in the environment is caused by external exposure to radiation from the soil. There is no policy - and indeed there never has been one - in this respect. There is a maximum allowable concentration for radionuclides in food. Food generally meets these requirements and it is only on isolated occasions that raised levels - particularly of caesium (137Cs) - are found in more exotic products, such as heather honey and game (boar, venison). In 2000 also, these levels did not exceed the limit of 600 Bq/kg.
Relevance
The average individual dose resulting from artificial radionuclides in the environment was approximately 12 µSv in 2000. This dose corresponds to ten deaths annually in the Netherlands (as a result of cancer).
Technical note
In the Netherlands, a range of institutions conduct systematic measurements of the environment. In order to coordinate these measurement programmes and in order to ensure the efficient monitoring of the environment, the Coordination Committee for Measurements in the Environment (CCRX) was established. As part of this initiative, the radiation dose generated by artificial sources in the environment was calculated annually on the basis of measurements. The calculations covered the dose as a result of radiation from radionuclides on the ground (external dose) and from the consumption of food containing radionuclides from the soil (internal dose). Because of the ongoing fall in radioactivity in food (partly as a result of radioactive decay and partly as a result of the reduction in availability for crops), food has only been measured on an intermittent basis since 1998. The figures from 1998 onwards have therefore been extrapolated, taking into account the radioactive decay referred to above and the level to which radioactivity is less available for uptake.
References
- CCRX (1994). Jaarverslag 1992 van de CCRX-werkgroep Meettechnieken Radioactiviteit. Ministry of Housing, Spatial Planning and the Environment, The Hague.
- CCRX (1995). Metingen in het milieu in Nederland 1993. Ministry of Housing, Spatial Planning and the Environment, The Hague.
- Eleveld, H., R.O. Blaauboer et al. (2002). Emissies en doses door bronnen van ioniserende straling in Nederland - Jaarrapport 2001 'Beleidsmonitoring straling'. RIVM (report no. 610 100 001), Bilthoven.
- Knetsch, G.J. (ed.) (2002). Monitoring of radiation in the environment in the Netherlands. Results in 2000. RIVM (report 610 056 047), Bilthoven.
