There could be more focus on how the ICRP RAP approach will complement ongoing work – particularly an acknowledgment of those counties and bodies that are already carrying out environmental impact assessment of ionising radiation. Are they expected to adapt or change their approach? How will the RAPs and/or DCLs supplement these assessments? By recognising the diverse species already included in site-specific EIAs, it could be an opportunity for ICRP to strengthen its vision of RAPs as a point of reference, or benchmark for inter-comparison.
Specific Comments – all related to the Reference Earthworm
Page 15. Table for selection criteria.
Earthworms are not considered as a human resource. That could be debatable, depending on how one defines what a resource is.
Regarding legislation, while not directly protected as wildlife, toxicity testing with earthworms is a legislative requirement in some countries before new chemicals can be released into the environment.
Page 20: paragraph 49: Characterization of the reference earthworm.
Use cocoons instead of capsules.
Why this particular set of characteristics for fecundity and reproductive rate? Which species is it supposed to be representative of? The given fecundity and reproductive rate are low compared to that for, for example Eisenia fetida, which is the most used in toxicity testing.
Page 23. Table 3. Earthworms are wrongly characterized as Semelparous. They reproduce more than once, and are hence iteroparous rather than semelparous.
(see also section 8.2 in appendix A: They are more or less continuous breeders, page 20)
Page 56. Mortality. The data presented is a mixture from studies on earthworms and other types of annelid worms. Be more specific on differences. For example, the LD50 values quoted for the adult annelids refer to the study of Harrison and Anderson 1994: This is a marine Polychaete worm.
Paragraph 186. Note that the observed field effects could be caused by reduced reproduction capacity rather then mortality.
Page 64. Morbidity.
Pargraph 220. Specify the species E. fetida.
Can add results from Hertel-Aas et al., 2007.
In a two-generational study, Hertel-Aas et al. (2007) found no significant effects of absorbed gamma dose rates up to 43 mGy/h on growth in adult F0 earthworms (E. fetida) during 13 weeks exposure (maximum accumulated dose 85 Gy). The growth of the F1 juveniles was not inhibited by the radiation exposure (dose rates up to 11 mGy/h) and there was no influence on the sexual maturation rate (maximum accumulated doses 24 Gy). In F1, some exterior abnormalities were observed at the highest dose rate (11 mGy/h). These included development of an asymmetrical and segmented clitellum in 5% of worms, which resulted in the production of “double cocoons”.
5.3.3 Reduced reproductive success
Paragraph 301: Incorrect citation of Hingston et al., 2004. The second sentence “Dose rates of 213.6 mGyd-1… “ refers to the woodlice experiments not earthworms. Check the original report...
Paragraph 302: Hopefully you have now received an actual copy of the Hertel-Aas paper refereed to in this paragraph? (We noted the request in reference list!). A brief summary is given below…
In a laboratory study performed by Hertel-Aas et al. (2007), Eisenia fetida was exposed continuously to 60Co gamma irradiation during 2 generations (F0 and F1). The reproduction capacity of adult F0 worms was measured over a 13 week exposure period in controls and at five dose rates (4.3, 40.8, 96, 264 and 1032 mGy/d; corresponding total accumulated doses 0.37, 3.56, 8.6, 23 and 85 Gy). Survival, growth and sexual maturation of F1 hatchlings were examined for 11 weeks at the four lowest dose rates, followed by a further 13 weeks exposure for registration of reproduction capacity (corresponding total accumulated doses 0.73, 7, 17 and 45 Gy). For F0, hatchability of cocoons produced during the first four weeks was reduced to 60% at 1032 mGy/d, and at this dose rate none of the cocoons produced during the following 5 to 13 weeks hatched. At 264 mGy/d a pronounced effect on cocoon hatchability was observed only at 9 - 13 weeks, when hatchability was reduced to 25%. Correspondingly, the total number of F1 hatchlings per adult F0 produced during the 13 weeks exposure period was reduced to 17% and 57% compared to the controls at 1032 mGy/d and 264 mGy/d, respectively. The total number of F1 hatchlings was reduced also at 96 mGy/d, but the effect was of borderline significance. At the end of adult F0 exposure, dissection and microscopic examination revealed atrophic male reproductive organs in worms exposed at 1032 mGy/h. For adult F1, the hatchability of cocoons produced at 264 mGy/h was reduced to 45 - 69% during the 13-week exposure period. The total number of F2 individuals produced per adult F1 was reduced to 37% compared to the controls.