Abstract
Perhaps the main factor determining success of space travel will be the ability to control effects of ionizing radiation for humans, but also for other living organisms. Manned space travel will require the cultivation of food plants under conditions of prolonged exposure to ionizing radiation. Although there is a significant literature concerning the effects of acute high dose rate exposures on plant genetics, growth, and development, much less is known concerning the effects of chronic low dose irradiation especially those related to the impacts of the high energy protons and heavy ions that are encountered in the space environment. Here, we make the argument that in situ studies of the effects of radionuclides at nuclear accident sites (e.g., Chernobyl and Fukushima), atomic bomb test sites, and areas of naturally high radiation levels, could provide insights concerning the mechanisms of radiation effects on living systems that cannot be assessed short of conducting research in space, which is not yet feasible for large scale, long term, multigenerational experiments. In this article we review the literature concerning the effects of chronic low-dose rate radiation exposure from studies conducted in Chernobyl, Fukushima, and other regions of the world with high ambient radiation levels (parts of India in particular). In general, mutation rates and other measures of genetic damage are considerably elevated, pollen and seed viability are reduced, growth rates are slower, and the frequency of developmental abnormalities is increased, although there is considerable variation among taxa for these effects. In addition, there are interactions between radiation and other environmental stressors (e.g., temperature, drought, heavy metals) that may play important roles in determining susceptibility to radiation induced stress.
Highlights
On this planet, ionizing radiation stems primarily from geological processes and is the result of the decay of radionuclides in the ground
Because most studies employ an acute, high dose rate exposure to gamma rays alone, these studies may have limited relevance for issues related to the effects of radionuclides in the soil from natural or anthropogenic sources
Development, and life history at terrestrial sites having large amounts of radionuclides offer an opportunity to experimentally investigate exposure to a wide range of ionizing radiation sources over long time periods that in some ways could be used as a proxy for studies of cosmic radiation
Summary
On this planet, ionizing radiation stems primarily from geological processes and is the result of the decay of radionuclides in the ground. This difference between studies could reflect the much higher sample sizes for the latter study or perhaps the impacts of evolved adaptations to radionuclides in general there is very little evidence to suggest that higher organisms (including plants) show much in the way of genetically based adaptive responses to ionizing radiation in the Chernobyl region (Møller and Mousseau, 2016).
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