Ionizing radiation is known for being dangerous at high doses, beneficial for diagnosis and treatment of diseases, and expensive for hazardous waste disposal and other protection policies governments put in place. Balancing the benefits and risks is key to maximizing public health, reducing public fears, and reducing extraneous costs that could have huge health benefits if spent more strategically. In order to strike the optimal balance, it is important to understand how ionizing radiation impacts health. Ionizing radiation comes from many sources at different dose rates with different total doses. Additionally, ionizing radiation impacts people differently based on age, gender, and confounding factors linked to lifestyle and genetic background all that contribute to health. Some such confounding factors include diet, exercise, smoking, heritable diseases, and environmental factors. We examined the risks associated with ionizing radiation under varying conditions using data from ten separate well-controlled animal studies conducted at Argonne National Laboratories. We performed a thorough statistical analysis to appropriately pool together mice from all ten experiments for a unique dataset. Our research showed that increased fractionation can significantly decrease the death hazard for mice exposed to gamma and neutron rays. When examining subgroups of mice based on their cause of death, we discovered that fractionated gamma ray exposures decreased the death hazard for all groups (lymphomas, tumors, non-tumors, and causes of death unknown) compared to acute exposures. Conversely, in neutron irradiated mice, only mice that experienced tumor-related deaths had significantly increased survival probabilities with increased fractionation. For both radiation qualities females were at a greater risk for all causes of death compared to male mice, except for lung tumors specifically. Neutron irradiated mice were more sensitive with age at first exposure to ionizing radiation with aged mice having significantly decreased death hazards compared to mice first irradiated at a younger age. In gamma irradiated mice, the most common cause of death was lymphomas, compared to solid tumors in neutron irradiated mice. The differences in health outcomes between the two radiation qualities can lead to novel hypotheses surrounding the mechanism of disease development in response to ionizing radiation. Increasing our understanding of the exact risks posed by ionizing radiation exposures can ultimately improve protective policies in place and optimize our use of radiation for healthcare. New analyses on existing archives, such as the one presented here, are essential as our current understanding of radiobiology and the most pressing radiobiology questions continue to change.

Creator

• Zander, Alia

DOI

• https://doi.org/10.21985/n2-a093-h854

Subject

• Biology

Language

• en

Alternate Identifier

• http://dissertations.umi.com/northwestern:15292
• etdadmin_upload_765069

Date created

• 2020-01-01

Resource type

• Dissertation

Rights statement

• In Copyright