For many years, protection of the environment from radiation was anthro­pocentric based on the ICRP statement2 that

“The Commission believes that the standard of environmental control needed to protect man to the degree currently thought desirable will ensure that other species are not put at risk. Occasionally, individual members of non-human species might be harmed, but not to the extent of endangering whole species or creating imbalance between species. At the present time, the Commission concerns itself with mankind’s environment only with regard to the transfer of radionuclides through the environment, since this directly affects the radiological protection of man’’.

Thus, the protection criterion for humans (1mSvy-1; see the following chapter by Pentreath) was considered to be sufficiently restrictive that popu­lations of non-humans living in the same environment would be sufficiently protected.

Over the last decade, systems of radiological protection for wildlife have begun to evolve with considerable international and national effort on this issue. In the 2007 Recommendations of the ICRP, the Commission recom­mended the explicit consideration of Radiological Protection of the Environ­ment and recognised the need for advice and guidance, including a clearer framework.3 In 2005, the ICRP formed a fifth committee, which deals speci­fically with the protection of the environment from ionising radiation. Com­mittee 5 proposed a framework for protection of the environment which uses the concept of Reference Animals and Plants (RAPs), designed to be compa­tible with the system of protection used for humans.4 The ICRP also aims to produce a system similar to those used for protection of the environment from other hazards.

The need for a system capable of demonstrating that the environment is adequately protected from the effects of radioactive substances has been recognised by international organisations (e. g. the International Atomic Energy Agency; IAEA)5 and a number of regulators. Environmental protection is now referred to in the International Atomic Energy Agency’s Fundamental Safety Principles.6 The forthcoming revision of the International Basic Safety Standards also mentions radiological protection of the environment. Different approaches have been developed to estimate the exposure of wildlife to ionising radiation. These approaches are used, in some countries, to address require­ments in national legislation to demonstrate that the environment is protected from anthropogenic releases of radioactivity.7 12 Radiation protection has not always been the driver of this process, in some countries a system of protection is required to address conservation legislation.

The ICRP4 has focussed on Reference Animals and Plants (RAPs) which are defined as follows

“A hypothetical entity, with the assumed basic biological characteristics of a particular type of animal or plant, as described to the generality of the taxonomic level of Family, with defined anatomical, physiological, and life — history properties, that can be used for the purposes of relating exposure to dose, and dose to effects, for that type of living organism’’.

The RAPs are hypothetical entities and not intended to represent a particular species. Commonly, in assessment approaches linked to tools, the approach taken to address the wide range of different wildlife species is to use ‘‘reference organisms’’. The selection of reference organisms has considered the need to encompass protected species, and different trophic levels and exposure path­ways.13,14 Reference organisms have tended to be defined at a broad wildlife group level (e. g. soil invertebrate, predatory fish, terrestrial mammal etc.). The definition of reference organisms used in the integrated Environmental Risk from Ionizing Contaminants Assessment and Management (ERICA) approach developed by EC researchers15 is

“a series of entities that provide a basis for the estimation of radiation dose

rate to a range of organisms which are typical, or representative, of a

contaminated environment. These estimates, in turn, would provide a basis

for assessing the likelihood and degree of radiation effects’’.

In contrast, for some approaches specific species rather than wide groupings have been considered.11,16

To assess the risk of radioactivity to wildlife we need an approach which contains the following components:

(i) transfer of radionuclides to wildlife;

(ii) dose conversion coefficients relating internal and media activity concentrations to estimate absorbed dose rates to wildlife; and

(iii) interpretation of the biological effects of radiation to determine the risk to wildlife.

There are currently three comparatively comprehensive assessment models which are freely available: the ERICA Tool which implements the ERICA Integrated Approach,17 RESRAD-BIOTA18 which implements the US Department of Energy’s Graded Approach9 and the England and Wales Environment Agencies R&D128.11,14