Hostname: page-component-76fb5796d-vvkck Total loading time: 0 Render date: 2024-04-26T06:35:58.964Z Has data issue: false hasContentIssue false
  • English
  • Français

Mathematical model approach to understand the ecological effect under chronic irradiation

Published online by Cambridge University Press:  09 January 2012

J. Barescut ,
D. Lariviere ,
T. Stocki ,
I. Kawaguchi ,
M. Doi  and
S. Fuma
I. Kawaguchi
Affiliation:
Research Center for Radiation Protection, National Institute of Radiological Sciences 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
M. Doi
Affiliation:
Research Center for Radiation Protection, National Institute of Radiological Sciences 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
S. Fuma
Affiliation:
Research Center for Radiation Protection, National Institute of Radiological Sciences 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
Get access

Abstract

Although aim of the environmental protection is conservation of ecosystem, there are only a few studies focusing on the effect of radiation on ecosystem. To understand the ecological effect of irradiation, microbial ecosystem, “microcosm”, which contains minimum components of ecosystem such as producer, consumer and decomposer, is useful because the natural ecosystem is too complex. The microcosm consists of three species, i.e. Euglena (producer), Tetrahymena (consumer), and E. coli (decomposer). The mathematical model and computer simulation model were also developed to understand the mechanism of ecological interaction using the results of acute exposure experiments of the microcosm, and we predicted Tetrahymena, which is the most radio-resistant among the constituent species, would be most sensitive in the chronically irradiated microcosm as a result of an indirect effect due to population decrease in E. coli. Recently we started chronic exposure experiments. The microcosms were irradiated with γ-rays at dose rate of 1.2Gy/day, 5Gy/day, 10Gy/day and 23Gy/day. From preliminary results, we found that the prediction from the models was different from the experimental results. Therefore, in this study, we improved our mathematical model and discuss the difference between the model and experiments.

Type
Research Article
Information
Radioprotection , Volume 46 , Issue 6: ICRER 2011 – International Conference on Radioecology & Environmental Radioactivity: Environment & Nuclear Renaissance , 2011 , pp. S535 - S538
Copyright
© Owned by the authors, published by EDP Sciences, 2011

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Kawabata, Z., Matsui, K., Okazaki, K., Nasu, M., Nakano, N., Sugai, T. (1995), J. Protozool. Research, 5, 23–26.
Fuma, S., Takeda, H., Miyamoto, K., Yanagisawa, K., Inoue, Y., Sato, N., Hirano, M., Kawabata, Z. (1998), Effects of γ-rays on the populations of the steady-state ecological microcosm, Int.J.Radiation biology, 74, 145–150.
Fuma, S., Takeda, H., Miyamoto, K., Yanagisawa, K., Inoue, Y., Ishii, N., Sugai, K., Ishii, C., Kawabata, Z. (2001), Ecological evaluation of gadolinium toxicity compared with other heavy metals using an aquatic microcosm. Bulletin. Environmental Cont. and Toxicol., 66, 231–238.
Fuma, S., Ishii, N., Takeda, H., Miyamoto, K., Yanagisawa, K., Ichimasa, Y., Saito, M., Kawabata, Z., Polikarpov, G.G. (2003), Ecological effects of various toxic agents on the aquatic microcosm in comparison with acute ionizing radiation. J. Environmental Radioactivity, 67, 1–14.
Shikano, S., Kawabata, Z. (2000), Effect at the ecosystem level of elevated atmospheric CO2 in an aquatic microcosm. Hydrobiologia, 436, 209–216.
Doi, M., and Kawaguchi, I. (2007), Ecological impacts of umbrella effects of radiation on the individual members. J. Environmental Radioactivity, 96, 32–38.
Doi, M., Kawaguchi, I., Tanaka, N., Fuma, S., Ishii, N., Miyamoto, K., Takeda, H., Kawabata, Z. (2005), Model ecosystem approach to estimate community level effects of radiation. Radioprotection, Suppl. 1, 40, S913–S919.
Fuma, S., Kawaguchi, I., Kubota, Y., Yoshida, S. Kawabata Z., and Polikarpov, G.G. Effects of chronic γ-irradiation on the aquatic microbial microcosm, submitted.
Shikano S., Luckinbill L.S., and Kurihara Y. (1990) Changes of traits in a bacterial population associated with protozal predation. Micro. Ecol. 20, 75–84.
Nakajima, T. and Kurihara, Y., (1994) Evolutionary changes of ecological traits of bacterial populations through predator-mediated competition., Oikos, 71, 24–34.