Institute of Development, Aging and Cancer, Tohoku University

Research

Seminars and Symposia

IDAC Seminar, 15 November 2013

Secretariat, Alumni Association, IDAC
Date Friday,15 November 2013, 16:00~
Room Seminar-shitsu 1, IDAC Research building 7F
Title Non-Human Animal Models for Effects of Radiation Exposure in Nature
Speaker Timothy A. Mousseau, PhD
Affiliation Professor of Biological Sciences, University of South Carolina
Person-in-charge Manabu FUKUMOTO Dept. Pathology
Contact : ken OHTSU (ex:8509)
Abstract Recently published scientific studies of the plants and animals living in Chernobyl, Fukushima and other naturally radioactive regions around the world provide strong evidence that exposure to ionizing radiation can lead to elevated mutation rates, higher frequencies of cataracts, reduced fertility and longevity, increased rates of developmental abnormalities and tumors, reduced biodiversity and population abundances, and even local extinction. Analysis of these findings indicate that there is no threshold radiation level below which biological consequences are not observed and that even very low levels of exposure can measurably impact natural populations, particularly following multiple generations of chronic exposure. A meta-analysis of published studies for populations in naturally radioactive regions of the world suggest some organisms can evolve resistance to radiation although there is no evidence for hormesis. A comparison of the impacts of radiation in Fukushima versus Chernobyl on identical passerine bird species suggests that selection has may have reduced apparent sensitivity to mutagens in Chernobyl during the past 27 years although many species remain significantly negatively impacted by high radiation levels. The main message from this presentation is that we now know that there are significant harmful consequences to many species from exposure to low-dose radiation such as is presently seen in parts of Chernobyl and Fukushima but that there is still very much more to be known before it will be possible to predict the long term impacts on ecosystems of nuclear accidents.