The Centers for Disease Control and Prevention (CDC) Radiation Laboratory’s primary mission is to provide laboratory support for an effective and efficient response to public health radiological emergencies. The laboratory has developed methods for several radiological threat agents, including Iridium-192 (Ir-192). Ir-192 can be analyzed via its gamma energy through analytical methods such as High Purity Germanium (HPGe) and its beta energy through Liquid Scintillation Counting (LSC). In this work, we present and compare HPGe and LSC rapid response methods for Ir-192 quantification. Both methods show the reasonable results and can be used in emergency situations. © This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply 2024.

Liquid Scintillation Counting (LSC) gross alpha/beta screening is a valuable tool for providing rapid laboratory response for the analysis of human clinical urine samples during a large-scale radiation incident event. Verification of method performance, as required for clinical laboratory testing, is accomplished by the evaluation of routine, periodic measurements of radioactive spiked samples for quality control, performance testing, and accuracy checks. Radionuclide stability of alpha and beta emitters in urine for LSC analysis is an important consideration. The purpose of this work is to demonstrate optimal preparations and storage conditions of samples used for method verification. © This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply 2024.

Rapid detection and quantification of gross alpha/beta-emitting radionuclides by liquid scintillation counting (LSC) is vital in guiding response to a nuclear or radiological incidents. Liquid scintillation counters use signal pulse shape to discriminate alpha and beta events in samples but require precise optimization to minimize the spillover, or misclassification, of those events. In this study, samples at varying activity levels were analyzed by LSC to determine the effect of activity level, emitter type, and sample matrix on spillover. Analysis proved a matrix effect and a direct correlation of activity level on spillover percentage for both alpha and beta emitting-nuclides. © 2023, This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.

As part of the Centers for Disease Control and Prevention’s post-radiological/nuclear incident response mission, we developed rapid bioassay analytical methods to assess possible human exposure to radionuclides and internal contamination. Liquid scintillation counting (LSC) is a valuable analytical tool for the rapid detection and quantification of gross alpha/beta-emitting radionuclides in urine samples. A key characteristic of this type of bioassay method is its detection sensitivity for the priority threat radionuclides. We evaluated the limit of detection of selected LSC instruments to determine which instrument can be used when low-dose measurement is important. © 2021, This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.

Responding to a radiological or nuclear incident may require assessing tens to hundreds of thousands of people for possible radionuclide contamination. The measurement of radioactive Sr is important because of its impact on people’s health. The existing analytical method for urine Sr-90 analysis using crown ethers is laborious and involves possible exposure to concentrated acids; therefore, this work is devoted to the development of the automated Sr-90 separation process, which became possible with the prepFast pre-analytical system (Elemental Scientific, Inc). © 2021, This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.

Radioactive strontium is a nuclear fission decay product found in industrial products and nuclear waste and is released during nuclear accidents. Current urine radiostrontium separation methods often are based on the use of Sr resin columns or cartridges (Eichrom Technologies). Most of these analytical methods use stable Sr as a tracer, with subsequent Sr recovery. The gravimetric recovery method requires 120 times more stable Sr than does the inductively coupled plasma mass spectrometry method described here. This difference can affect cartridge performance especially with aging cartridges. © 2021, This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.

Nuclear industry advancements and growing concerns about environmental contamination and terrorist activity have increased interest in quantifying radioisotopes in environmental and human samples. Increased presence in the environment, ease of entry into the food chain, nuclear medicine applications, and the possibility of radiological terrorism incidents can lead to human intake of these radionuclides (Radionuclides/Radiation Protection/US EPA (2020). https://www.epa.gov/radiation/radionuclides; Radiation from the Earth (Terrestrial Radiation) (2015) Radiation and Your Health, Centers for Disease Control and Prevention. 7 December. https://www.cdc.gov/nceh/radiation/terrestrial.html). A universal method to screen for and quantify individual radionuclides as well as both levels of alpha and beta emitters would address these concerns.

In the case of a radiological or nuclear incident, valuable information could be obtained in a timely manner by using liquid scintillation counting (LSC) technique through fast screening of urine samples from potentially contaminated persons. This work describes the optimization of LSC parameters on PerkinElmer (PE) Tri-Carb and Quantulus GCT series instruments to develop a rapid method for screening urine in an emergency response situation.

Following a radiological or nuclear incident, the National Response Plan has given the Department of Health and Human Services/Centers for Disease Control and Prevention the responsibility for assessing population’s contamination with radionuclides. In the public health response to the incident, valuable information could be obtained in a timely and accurate manner by using liquid scintillation counting techniques to determine who has been contaminated above background for alpha and beta emitting radionuclides. The calibration plays a major role in this process therefore, knowing the effect of quench agents on calibration is essential.