Man is exposed to slow doses of ionizing radiation from natural and man-mad sources, rendering there increased interest in the study of its biological effects.Vibrational spectroscopies such as Fourier transforms for infrared and Raman micro-spectro-scopies, have been used to study high doses of ionizing radiation on biosystems, trying to clarify their potential role for monitoring change in cells. The absorbed energy averaged across the target mass exposed is thought to determine the danger to a particular organ or tissue under the present radiological protection system. The duration of the dose delivery, the kind of ionizing radiation that caused the energy deposition, and the total absorbed dosage all affect the exposure's biological consequence (radiation quality). For radiation protection, a single dose and dose rate effectiveness factor (DDREF) is presently used to account for the effects of dosage and the temporal variation in dose delivery. However, as evidenced by earlier and ongoing work conducted in Task Group 91 of the International Criminal Court, the evidence foundation for this decision is still up for contention Commission on Radiological Protection (ICRP) . Medical workers represent the largest occupational group exposed to man-made sources of ionizing radiation. Although recorded radiation doses among medical personnel have markedly decreased over the past century, certain practices—such as fluoroscopy-guided procedures and nuclear medicine—still involve relatively high exposure levels. Physical dosimetry is commonly used to estimate annual occupational doses; however, reliance on personal dosimeters may lead to inaccurate dose assessment due to limited detector sensitivity and inadequate compliance with radiation protection guidelines. In addition, the growing use of fluoroscopic techniques by physicians with insufficient radiation safety training increases both exposure risk and the likelihood of dose underestimation. Studies indicate that many fluoroscopy operators do not consistently apply protective measures, including regular dosimeter use and appropriate shielding. Therefore, biological dosimetry offers a valuable complementary approach for more accurate evaluation of radiation exposure and its biological effects in medical workers. Ionizing radiation and radioactivity were identified in the late nineteenth century; however, global concern regarding radiation as an environmental hazard intensified following the deployment of nuclear weapons during World War II. The proliferation of nuclear armament programs, nuclear testing, and major nuclear accidents such as Chernobyl (1986) and Fukushima (2011) has substantially increased environmental radioactive contamination. Moreover, the extensive use of nuclear energy and the long-term accumulation of radioactive waste further contribute to radiation exposure in the environment. Widespread applications of ionizing radiation in medical diagnostics and scientific research have resulted in occupational and public exposure to low radiation doses. Although epidemiological evidence indicates no definitive adverse health effects at doses below 100 mSv—and some studies suggest potential beneficial effects—these observations remain highly debated. Consequently, this review aims to elucidate the health implications of acute radiation syndrome and chronic radiation effects, which may pose significant risks to human health. Radiation-induced tissue effects occur in nearly all normal tissues and may involve interactions among multiple organs. Early responses primarily affect rapidly proliferating tissues, leading to hypoplasia, whereas late effects arise from combined parenchymal, vascular, and connective tissue damage, resulting in functional loss. Consequential late effects emerge from the interaction between early and late responses, while very late effects are largely driven by vascular alterations, with consistent involvement of the immune system. The latency of late effects is inversely related to the biologically equieffective dose, and each tissue component exhibits a distinct dose–response relationship. Exposure conditions, particularly dose rate reduction and dose fractionation, strongly influence late-responding tissues, whereas overall exposure duration mainly affects early reactions. The clinical consequences of partial organ irradiation depend on tissue architecture, highlighting the need for biomarkers to predict individual risk and strategies to mitigate radiation-induced tissue damage.