LTC H. Michael Stewart Jr.
Future Forces Forum Future Forces Exhibition 2016 Medical Workshop 2016
Chemical, Biological, Radiation, and Nuclear Branch Chief, Health Care Operation Directorate, Headquarters, Department of the Army Office of The Surgeon General
Army Office of the Surgeon General/MEDCOM
US Radiological Agent Analysis
Co-presentation with Mr. Carl A. CURLING
This presentation identifies and illustrates the applicability of using a novel measure of hazard to evaluate the credibility of a radioisotope to pose a threat in a specified radiological weapon scenario. The analysis identifies the radioisotopes of interest from within the full spectrum of radiological threats. Thirty one radioisotopes were evaluated for their credibility as radiological weapons under seven different routes of exposure (or types of radiological weapons), including external irradiation from a point source or contaminated ground; aerosol exposure by inhalation, ingestion, contamination, and submersion in contaminated air; and immersion in a radioactive gas. The novel measure, a ratio of the activity of a radioisotope found in commercial practice (“P”) with the amount of radioactive material to cause concern (“C”) within a specified scenario, is described. The P/C ratio is an indication of enough radioactive material is available to credibly construct a radiological weapon for the given scenario. It is useful in limiting the number of different radioisotopes considered. Further work can be done to address physical form, security, and other aspects which limit the utility and availability of radioisotopes, and there by limit the credibility of using them in a radiological weapon scenario.
Native of Kansas, he earned a Bachelor’s Degree in Nuclear Engineering in 1994 from Kansas State University and a Master’s Degree in Radiation Health Physics in 2005 from Oregon State University. He has been Diplomate of the American Board of Health Physics since 2008 and he completed Command and General Staff College in 2010. Lieutenant Colonel Stewart was commissioned as a Second Lieutenant in the US Army Medical Service Corps as a Nuclear Medical Science Officer in 1998 and assigned to Brooke Army Medical Center, as a Staff Health Physicist. Upon completion of his tour, he was assigned to Moncrief Army Community Hospital where he served as the Radiation Safety Officer. He was subsequently selected to pursue a Master’s degree and was assigned to the US Army Medical Department Student Detachment with duty at Oregon State University. Following his graduation, he was assigned to Madigan Army Medical Center as the Radiation Safety Officer for the Western Regional Medical Command and the Medical Center. He was then assigned to Eisenhower Army Medical Center, where he served as the Radiation Safety Officer for the Southeast Regional Medical Command and the Medical Center. While at Eisenhower Medical Center, he deployed with the 1st Medical Brigade and served as the United States Forces – IRAQ Command Radiation Safety Officer and the Theater Army Radiation Safety Consultant. He was then assigned to Public Health Command District – Northern Europe where he served as the Executive Officer and the European Regional Medical Command Radiation Safety Consultant. Lieutenant Colonel Stewart is currently serving as the Chemical, Biological, Radiation, and Nuclear Branch Chief, Health Care Operation Directorate, Headquarters, Department of the Army Office of The Surgeon General.