Ionizing radiation has been a primordial part of the planet earth and it might be the main reason why live could florish here. All living organisms, like humans, are being exposed to many natural, civilisatoric and technical irradiations from various sources and to various degrees. Often individuals, groups, administrations and government are very much concerned about at most very small individual radiation risks, i.e. about possible health effects of low dose rates of ionizing radiation (below, say, 10 mSv/yr). Radiation research over more than 50 years in vain has tried to improve our quantitative knowledge on such radiation health effects.
A main reason for this failure of answering such important questions is the principally wrong research strategy of concentrating main efforts on radiation effect investigations of single molecules (e.g. DNA) or of single cells (mainly in vitro). However, most health effects of living, adaptive organisms most likely actually result from rather indirect, systemic, emergent, responses at different levels of tissue organisation which, in principle, can never reductionarily be studied with single objects in isolation. In this contribution, a more promising research strategy, namely that of Systems Radiation Biology (SRB), will be outlined and justified. In this quantitative, more top-down, SRB - approach quantitative hypotheses on relevant action pathways of organismic homoestasis and its disturbances by external agents are being formulated and tested in close co-operations of theorists and experimentalists educated in different relevant disciplines (mathematics, physics, chemistry, biology, medicine, epidemiology, etc.).