Effects of Ionizing Radiation Combined with Other Stressors, on Non-Human Biota

Conference paper
Part of the NATO Science for Peace and Security Series book series (NAPSC)

Exposure of organisms in the environment to ionizing radiation is generally considered to be harmful, regardless of the dose. This assumption derives directly from the basic assumption used for human radiation protection, that harm is directly proportional to dose, without a threshold. The consequence of combined exposures is generally unknown, but is assumed to be either additive or multiplicative. We have examined the in vivo and in vitro responses of a variety of cells and organisms. We show that exposure to one stressor can influence the outcome of a subsequent exposure to the same or another stressor. In many cases, pre-exposure to one stressor appeared to induce an adaptive response that mitigated the harm from a second stressor. These observations challenge the basic assumptions used in environmental protection strategies, suggesting that new approaches are needed. Keywords: combined stressors; radiation; heat; chlorine; non-human biota


Combine Stressor Subsequent Exposure Chlorine Concentration Combine Exposure Binucleate Cell 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Calabrese, E. J., 2004, Hormesis: from marginalization to mainstream; A case for hormesis as the default dose-response model in risk assessment. Toxicol. Appl. Pharmacol. 197: 125–136.CrossRefGoogle Scholar
  2. Calabrese, E. J. and Baldwin L. A., 2000, The effects of gamma rays on longevity. Biogerontology 1: 309–319.CrossRefGoogle Scholar
  3. Calabrese, E. J. and Baldwin L. A., 2003a, The hormetic dose-response model is more common than the threshold model in toxicology. Toxicol. Sci. 71: 246–250.CrossRefGoogle Scholar
  4. Calabrese, E. J. and Baldwin L. A., 2003b, Toxicology rethinks its central belief. Nature 421: 691–692.CrossRefGoogle Scholar
  5. Mitchel, R. E. J., 2006, Low doses of radiation are protective in vitro and in vivo: Evolutionary origins. Dose Response 4: 75–90.CrossRefGoogle Scholar
  6. Mitchel, R. E. J. and Morrison D. P., 1982, Heat-shock induction of ionizing radiation resistance in saccharomyces cerevisiae. Transient changes in growth cycle distribution and recombinational ability. Radiat. Res. 92: 182–187.Google Scholar
  7. Mitchel, R. E. J., Jackson, J. S., McCann, R. A. and Boreham, D. R., 1999, Adaptive response modification of latency for radiation-induced myeloid leukemia in CBA/H mice. Radiat. Res. 152: 273–279.CrossRefGoogle Scholar
  8. Parsons, P. A., 2000, Hormesis: an adaptive expectation with emphasis on ionizing radiation. J. Appl. Toxicol. 20: 103–112.CrossRefGoogle Scholar
  9. Parsons, P. A., 2002, Radiation hormesis: challenging LNT theory via ecological and evolutionary considerations. Health Phys. 82: 513–516.CrossRefGoogle Scholar
  10. Parsons, P. A., 2003, Metabolic efficiency in response to environmental agents predicts hormesis and invalidates the linear no-threshold premise: ionizing radiation as a case study. Crit. Rev. Toxicol. 33: 443–449.CrossRefGoogle Scholar

Copyright information

© Springer 2007

Authors and Affiliations

  1. 1.Atomic Energy Canada Ltd.Chalk RiverCanada

Personalised recommendations