A Cyclotron Decommissioning Radiological Assessment Exercise Performed by Student Mentees Underrepresented in the Radiation Safety Profession.

Cyclotrons used in nuclear medicine imaging accelerate protons, deuterons, and helium ions to bombard a target, which produces nuclear reactions that generate positron-emitting radionuclides. Secondary neutrons are nonuniformly emitted in these reactions and induce heterogeneous activation of the cyclotron components and concrete vault enclosure. This poses radioactive waste management complications when decommissioning a cyclotron facility, since the objective is to ensure that exposures are within regulatory limits and as low as reasonably achievable (ALARA). The McGovern Medical School in The University of Texas Health Science Center in Houston housed a Scanditronix MC40 cyclotron that produced short-lived radioisotopes for Positron Emission Tomography (PET) imaging from 1984 to 2001 until Tropical Storm Allison rendered it inoperable. The purpose of this study was to provide underrepresented Science, Technology, Engineering and Mathematics (STEM) students an ALARA experience with a practical problem encountered in the radiation safety profession. Gamma dose rate measurements were performed with both a Mirion InSpector 1000 spectrometer and Fluke 451P survey meter in the vault at locations identified as hotspots based on preliminary scoping surveys with the Ludlum model 44-9 detector. However, gamma spectra were measured with the spectrometer exclusively at hotspots along the west wall. Results indicated the maximum gamma dose rate of 129 ± 31 nSv h was about 2 times background near the central beam transport line of the now inoperable cyclotron. Furthermore, gamma emission peaks were identified in the spectra from trace amounts of Co and Eu in the vault's concrete walls.

Trends and associated characteristics for Chagas disease among women of reproductive age in the United States, 2002 to 2017.

BACKGROUND: American trypanosomiasis, commonly referred to as Chagas disease, is caused by a single cell protozoan known as Trypanosoma cruzi (T. cruzi). Although those affected are mainly in Latin America, Chagas has been detected in the United States (US), Canada and in many European countries due to migration. Few studies have explored the epidemiology of Chagas within the US or changes in disease burden over the past decade. The objective of this study was to explore the trends and associated characteristics for Chagas disease among hospitalized women of reproductive age in the US. METHODS: We analyzed admissions data including socio-demographic and hospital characteristics for inpatient hospitalization for women of reproductive age (15-49 years) in the US from 2002 through 2017. We employed Joinpoint regression analysis to determine trends in the prevalence of Chagas disease over this period. RESULTS: A total of 487 hospitalizations of Chagas disease were identified, corresponding to 3.7 per million hospitalizations over the study period. The rate statistically increased from 1.6 per million in 2002 to 7.6 per million hospitalizations in 2017. Chagas was most prevalent among older women, Hispanics and those in the highest zip income bracket. The in-hospital mortality rate was about 10 times greater among women with Chagas compared to those without the condition (3.1% versus 0.3%), and the condition tended to be clustered in women treated at large, urban teaching hospitals in the Northeastern region of the US. CONCLUSION: Chagas disease diagnosis appears to be increasing among hospitalized women of reproductive age in the US with a 10-fold elevated risk of mortality.