Award Date

8-1-2016

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Health Physics and Diagnostic Sciences

First Committee Member

Gary Cerefice

Second Committee Member

Steen Madsen

Third Committee Member

Francis Cucinotta

Fourth Committee Member

Daniel Young

Number of Pages

81

Abstract

The ICRP has published two biokinetic models providing a basis for radiation dose assessment due toradionuclides incorporated inside the gastrointestinal tract. These models are a sufficient tool to assess the committed dose equivalent for occupational exposures to workers assuming normal anatomy. The colostomy is becoming a more prevalent procedure. A colostomy permanently or temporarily bypasses a portion of colon to allow rest and healing. There are four different colostomies; ascending, transverse, descending and sigmoid and an ileostomy. As a patient’s strength returns, they can return to normal daily activities, including returning to work. Therefore, as an ostomy patient returns to the workforce handling radioactive material, the potential for exposure to the radioactive material for these workers increases. The aim of this project is to determined whether or not an additional risk exists for these workers and if additional limitations should be placed on ostomy patients handling uranium. In order to determine if an additional risk exists two pathways are considered, ingestion and injection. Injection is a unique pathway for this work and is defined as radioactive material entering through the stoma. As part of the injection scenario as well as in the event contamination occurs, the dose per hou to the stoma was also determined. Using modified ICRP 30 gastrointestinal models and ICRP 100 HATM models to reflect the anatomy changes for each procedure, the committed dose equivalent (CDE) and committed effective dose equivalent (CEDE) was determined for each procedure. In addition, using the more limiting value between the CDE and CEDE annual limit, the annual limit on intake (ALI) was determined. Based on a decrease in CDE values within the alimentary tract for each procedure and the determination the ALIs were either equivalent or orders of magnitude greater than the current ICRP ALI values no additional risk exists. Finally, based on the dose per hour resulting from stoma contamination, the chemical hazards were determined to be of greater concern than the radiological. Therefore, no additional guidance is needed for ostomy patients working with uranium.

Disciplines

Medicine and Health Sciences | Nuclear

File Format

pdf

Degree Grantor

University of Nevada, Las Vegas

Language

English

Rights

IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/


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