Ionizing radiation biomarkers for potential use in epidemiological studies

Abstract

Ionizing radiation is a known human carcinogen that can induce a variety of biological effects depending on the physical nature, duration, doses and dose-rates of exposure. However, the magnitude of health risks at low doses and dose-rates (below 100mSv and/or 0.1mSvmin(-1)) remains controversial due to a lack of direct human evidence. It is anticipated that significant insights will emerge from the integration of epidemiological and biological research, made possible by molecular epidemiology studies incorporating biomarkers and bioassays. A number of these have been used to investigate exposure, effects and susceptibility to ionizing radiation, albeit often at higher doses and dose rates, with each reflecting time-limited cellular or physiological alterations. This review summarises the multidisciplinary work undertaken in the framework of the European project DoReMi (Low Dose Research towards Multidisciplinary Integration) to identify the most appropriate biomarkers for use in population studies. In addition to logistical and ethical considerations for conducting large-scale epidemiological studies, we discuss the relevance of their use for assessing the effects of low dose ionizing radiation exposure at the cellular and physiological level. We also propose a temporal classification of biomarkers that may be relevant for molecular epidemiology studies which need to take into account the time elapsed since exposure. Finally, the integration of biology with epidemiology requires careful planning and enhanced discussions between the epidemiology, biology and dosimetry communities in order to determine the most important questions to be addressed in light of pragmatic considerations including the appropriate population to be investigated (occupationally, environmentally or medically exposed), and study design. The consideration of the logistics of biological sample collection, processing and storing and the choice of biomarker or bioassay, as well as awareness of potential confounding factors, are also essential.

Low doses of ionizing radiation induce immune-stimulatory responses in isolated human primary monocytes

“…One of the challenging factors in the study of the health effects of exposures to low doses of ionizing radiation is the lack of epidemiological data, primarily due to confounding factors related to inter-individual variability, life style, and genetic background (3). Furthermore, in contrast to the well-studied mechanisms and the thoroughly investigated health effects of high doses, where cancer is a well-validated endpoint, the mechanisms and the biological responses, induced by low doses of ionizing radiation, are largely not agreed upon in the published studies (4).…”

Concerted Uranium Research in Europe (CURE): toward a collaborative project integrating dosimetry, epidemiology and radiobiology to study the effects of occupational uranium exposure

“…In addition, further improvements to the understanding and quantification of biological and health effects of uranium exposure can be gained through integrated epidemiological and radiobiological research (Laurier et al 2012, Pernot et al 2012, Kreuzer et al 2015a. One way to do this would be to conduct molecular epidemiological studies, by integrating the use of biomarkers in epidemiological studies (Palmer 2007, Zins et al 2010, Kreuzer et al 2015a.…”

Toxicogenetic biomonitoring of occupational risk induced by ionizing radiation

“…Among the risk factors, nowadays, radiation and its impacts on human health is a major concern to the etiology of cancer (Samet, 2011). On this occasion, extensive researches are needed in order to diagnose the problems to avoid or at least minimize the deleterious effects of ionizing radiation (IR) (Pernot et al, 2012).…”