Environmental Protection - the Concept and Use of Reference Animals and Plants
ICRP Publication 108Ann. ICRP 38 (4-6), 2008
Abstract - In its latest recommendations for a system of radiological protection, the Commission considered it necessary and appropriate to broaden its scope in order to address, directly, the subject of protection of the environment, although it acknowledged that there is no simple or single universal definition of ‘environmental protection’, and that the concept differs between countries and from one circumstance to another. It is a very large and complicated subject. Nevertheless, the Commission did consider it appropriate to set out some high-level ambitions with regard to environmental protection and the specific issue of potential radiation effects, and thus included within its general aims those of wishing to prevent or reduce the frequency of deleterious radiation effects in the environment to a level where they would have a negligible impact on the maintenance of biological diversity, the conservation of species, or the health and status of natural habitats, communities, and ecosystems. It also recognised the needs of some national authorities to demonstrate, directly and explicitly, that the environment is being protected within
their own legislative frameworks.
The Commission also stated, however, that it believed that its approach to environmental protection should be commensurate with the overall level of risk (and thus optimised), and that it should be compatible with other approaches being made to protect the environment. Some form of numerical guidance is therefore necessary,
and the Commission said that it considered that such guidance – built on a knowledge of the relationships between exposure and dose, between dose and effect, and between effect and possible consequences – needed to be based on a sound scientific system similar to that developed for human protection, and that this could best be achieved by the creation of a set of Reference Animals and Plants.
This publication therefore introduces the concept of Reference Animals and Plants, and defines a small set. It discusses their pathways of exposure, and collates and discusses the adequacy of the best-available data relating to their dosimetry at different stages of their life cycles. In addition, this publication further develops and uses this information to derive sets of tabulated data (dose conversion factors, in terms of (µGy/day)/(Bq/kg)) that allow the dose to be calculated for 75 radionuclides that may be within, or external to, each organism.
This publication reviews what is known about the effects of radiation upon such biotic types (or of similar organisms, where more precise data are lacking) with regard to the effects of mortality, morbidity, reduced reproductive success, and chromosomal damage. Drawing on this information, the report derives a set of derived consideration reference levels for each biotic type in order to help optimise the level of effort that might be expended on its environmental protection, or that of similar types of organisms, and thus serve as points of reference in any wider consideration
of what authorities may wish to do under different exposure situations.
The various factors that should be taken into account when considering what to do if the derived consideration reference levels are likely to be attained are also discussed. Some broader background information on the types of animals and plants used is also given. Additional information is provided on advice with regard to extrapolating
and interpolating the limited set of dosimetric models to other shapes and sizes of animals and plants.
The Commission acknowledges that, in many circumstances, exposure to radiation is but one factor to consider. It therefore intends to provide high-level guidance and advice upon which regulators and operators may draw in order to demonstrate compliance, where necessary, with the wide range of international and national environmental legislation that already exists, or is likely to emerge in the near future.
It also intends to supplement this introductory report with additional relevant data sets, and with further guidance on issues such as radiation weighting factors.