Individual Radiation Sensitivity
People Are Often Exposed to Low-Dose Ionizing Radiation
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Every day, people encounter low levels of ionizing radiation — from medical imaging procedures like X-rays and CT scans to occupational exposure and environmental sources such as radon gas or cosmic rays during air and space travel. While the doses are generally considered safe, growing evidence suggests that even low-dose exposure can have long-term health consequences, especially in individuals who are more biologically sensitive to radiation.
Common Sources of Low Dose Radiation
Medical Scans
Natural Radiation
Nuclear Accidents
Transatlantic Flights
Not Everyone Is Equally Affected
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A key challenge in radiation safety is that individual sensitivity varies widely. Factors that influence how the body responds to radiation include:
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Genetic predisposition
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Age and sex
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Preexisting health conditions
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Nutritional status
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Environmental co-exposure
Some individuals may tolerate repeated low-dose exposures with minimal risk, while others may suffer adverse effects after limited exposure. Yet current radiation protection guidelines are largely one-size-fits-all.
Identify Who Is More Vulnerable — Before Exposure Happens
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We are developing a cell-based assay platform to evaluate individual sensitivity to ionizing radiation using blood-derived progenitor cells, including Endothelial Colony-Forming Cells (ECFCs). These cells play a vital role in maintaining vascular health and are highly responsive to radiation-induced stress. By analyzing how a person’s ECFCs respond to controlled radiation exposure in vitro, we aim to identify individuals with heightened sensitivity.
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Knowing who is more vulnerable to radiation can help:
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Personalize medical imaging protocols
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Guide occupational exposure limits
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Reduce unnecessary risks for sensitive populations
Publications
Donor-Specific Cell-Based Assays in Studying Sensitivity to Low-Dose Radiation: A Population-Based Perspective
Front Public Health. 2014; 2: 244.
Dora Il’yasova, Alexander Kinev, C. David Melton, and Faith G. Davis
Abstract
Currently, a linear no-threshold model is used to estimate health risks associated with exposure to low-dose radiation, a prevalent exposure in the general population, because the direct estimation from epidemiological studies suffers from uncertainty. This model has been criticized based on unique biology of low-dose radiation. Whether the departure from linearity is toward increased or decreased risk is intensely debated. We present an approach based on individual radiosensitivity testing and discuss how individual radiosensitivity can be assessed with the goal to develop a quantifiable measure of cellular response that can be conducted via high-throughput population testing.
Endothelial colony forming cells (ECFCs) as a model for studying effects of low-dose ionizing radiation: growth inhibition by a single dose.
Cancer Invest. 2013 Jun;31(5):359-64. doi: 10.3109/07357907.2013.789903. Epub 2013 Apr 26.
Alexander V. Kinev, Vrad Levering, Kenneth Young, Francis Ali-Osman, George A. Truskey, Mark W. Dewhirst, and Dora Il’yasova
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Abstract
Identification of measurable nontransient responses to low-dose radiation in human primary cell cultures remains a problem. To this end, circulating endothelial colony-forming (progenitor) cells (ECFCs) were examined as an experimental model. ECFCs were isolated from three cord blood donors. Cells were positive for endothelial cell markers and remained highly proliferative after long-term cryopreservation. A single dose of X-ray radiation (0.06–0.38 Gy) inhibited ECFC culture growth. This effect was evident at 48 hours and persisted up to 72 hr postirradiation. Such protracted cytostatic response of ECFCs to low-dose radiation suggests that ECFC primary cultures can be used to study low-dose radiation effects.
METHOD FOR DETERMINING THE SENSITIVITY OF AN INDIVIDUAL TO LOW DOSE IONIZING RADIATION
United States Patent Application 20150355164. December 10, 2015.
Kinev; Alexander V ; Il'yasova; Dora; Dewhirst; Mark W.;
Abstract
​The present invention relates to the innovation that ECFCs are a predictor of the likely result to the exposure of a patient to low dose ionizing radiation by comparing the results of exposure of cells to individuals already exposed to ECFCs.