Factors governing individual response to ionizing radiation and risk of diseases of the circulatory system: human epidemiological studies

Purpose: Growing evidence from the Japanese atomic bomb survivors, and occupationally and medically exposed groups indicates that ionizing radiation could increase the risk of various diseases of the circulatory system (DCS), even at low levels of exposure. As radiation protection systems increasingly consider the possibility of individualized radiation protection, better understanding is needed of the factors that may impact radiation-related risk, whether intrinsic (such as age, sex or genetics), or extrinsic (such as smoking). Here, we comprehensively review potential effect modification of radiation exposure and the risk of DCS in medical, occupational and environmental settings.Conclusion: Several studies indicate potential effect modification, usually detrimental, with use of anthracycline in medical settings. There was some indication that younger age at exposure increased risk for various DCS outcomes, but this was less consistent across studies and settings. Interpretation of the data is complicated by considerations of statistical power, differences in specific disease outcomes, and narrow ranges of exposure and/or potential modifiers within studies. Future studies with well-defined exposure over a wide range of ages, along with biological samples, are required to better inform the nature of these interactions.