Alonzo F, Hertel-Aas T, Gilek M, Gilbin R, Oughton D H, Garnier-Laplace J
Laboratory of Environmental Modelling, DEI/SECRE/LME, Institute of Radioprotection and Nuclear Safety (IRSN), Cadarache, Building 159, BP3, 13115 St-Paul-lez-Durance Cedex, France.
J Environ Radioact. 2008 Sep;99(9):1464-73. doi: 10.1016/j.jenvrad.2007.11.021. Epub 2008 Mar 7.
This study evaluated the potential effect of ionising radiation on population growth using simple population models and parameter values derived from chronic exposure experiments in two invertebrate species with contrasting life-history strategies. In the earthworm Eisenia fetida, models predicted increasing delay in population growth with increasing gamma dose rate (up to 0.6 generation times at 11 mGy h(-1)). Population extinction was predicted at 43 mGy h(-1). In the microcrustacean Daphnia magna, models predicted increasing delay in population growth with increasing alpha dose rate (up to 0.8 generation times at 15.0 mGy h(-1)), only after two successive generations were exposed. The study examined population effects of changes in different individual endpoints (including survival, number of offspring produced and time to first reproduction). Models showed that the two species did not respond equally to equivalent levels of change, the fast growing daphnids being more susceptible to reduction in fecundity or delay in reproduction than the slow growing earthworms. This suggested that susceptibility of a population to ionising radiation cannot be considered independent of the species' life history.
本研究使用简单的种群模型以及从两种具有不同生活史策略的无脊椎动物的慢性暴露实验得出的参数值，评估了电离辐射对种群增长的潜在影响。在蚯蚓赤子爱胜蚓中，模型预测随着伽马剂量率增加，种群增长延迟加剧（在11毫戈瑞/小时时延迟增加至0.6代时间）。预测在43毫戈瑞/小时时种群灭绝。在微型甲壳动物大型溞中，仅在连续两代暴露后，模型预测随着阿尔法剂量率增加，种群增长延迟加剧（在15.0毫戈瑞/小时时延迟增加至0.8代时间）。该研究考察了不同个体终点变化（包括存活、产生的后代数量和首次繁殖时间）对种群的影响。模型显示，两种物种对同等程度的变化反应不同，快速生长的大型溞比生长缓慢的蚯蚓更容易受到繁殖力降低或繁殖延迟的影响。这表明，不能脱离物种的生活史来考虑种群对电离辐射的敏感性。
