Consideration of Background Radiation in Ecological Risk Assessments

Background or ambient concentrations are often considered in the evaluation of potential risks to ecological receptors from exposure to hazardous chemicals in the environment. Such an evaluation may be a component of the screening or final risk management process and sets the baseline from which risks contributed by site-related activities can be addressed. Although the process for the evaluation of potential radiological risks to ecological receptors is less formalized than the chemical hazard assessment process, background remains an issue that should be addressed when considering potential site-related impacts. This paper briefly presents the ecological risk assessment approaches used to address background radionuclide concentrations at three United States Department of Defense Facilities. The concepts of total radiation dose, and tolerance and adaptation of populations to radiation are also discussed within the context of background radiation.