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.

A method for determining activity of Sr and Sr in a sample where Sr and Y are not in equilibrium is presented. The method consists of an experimental design and equations for accurately calculating activity of Sr and Sr based on Y particle counts and the total counts of particles emitted from Sr, Sr, and Y in a sample. The equations are derived based on chemical separation sequences, particle counting sequences, and the Bateman equation. The presented method allows simultaneously obtaining the activity of Sr and Sr in a non-equilibrated Sr/Y system without the need of Cerenkov counting.

Three-dimensional printing and casting materials were analyzed by prompt gamma-ray activation analysis (PGAA) to determine their suitability as human tissue surrogates for the fabrication of phantoms for medical imaging and radiation dosimetry applications. Measured elemental compositions and densities of five surrogate materials simulating soft tissue and bone were used to determine radiological properties (x-ray mass attenuation coefficient and electron stopping power). When compared with radiological properties of International Commission on Radiation Units and Measurements (ICRU) materials, it was determined that urethane rubber and PLA plastic yielded the best match for soft tissue, while silicone rubber and urethane resin best simulated the properties of bone.

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.

The isolation and purification of protactinium from uranium materials is essential for Pa-U radiochronometry, but separating Pa from uranium-niobium alloys, a common material in the nuclear fuel cycle, is challenging due to the chemical similarity of Pa and Nb. Here we present three resin chromatography separation techniques for isolating Pa from U and Nb which were independently developed by three different laboratories through ad hoc adaptations of standard operating procedures. Our results underscore the need for and value of purification methods suitable for a diversity of uranium-based materials to ensure the operational readiness of nuclear forensics laboratories.

The need to generate objective evidence and reliable information for decision makers to improve environmental policies for a better air quality, led us to evaluate the atmospheric aerosol components in the urban area of Carabayllo, by monitoring PM and PM to determine mass concentration and analyzing PM using -INAA and ICP-MS for metals quantification, ion chromatography for anions and the NIOSH method to determine organic and elemental carbon. The results obtained from mass concentration of PM and PM exceeded the permissible breathing annual average of WHO guidelines of 15 µgm and 45 µgm, respectively, which evidence an unhealthy air quality. Likewise, using the model Positive Matrix Factorization five sources of pollutants were defined: metallurgical industry, sea salt, industrial activity, dust and non-exhaust emissions and vehicle emissions.

New values of neutron fluxes and spectral parameters and were determined experimentally in all irradiation devices of the TRIGA Mark I IPR-R1 nuclear research reactor at Nuclear Technology Development Centre (CDTN), Belo Horizonte, Brazil. Sets of monitors Au, Fe, Zn and Zr were irradiated bare and Cd-covered, according to "Cd-ratio for multi-monitor" method. Values were validated by analysing the certified reference material BCR-320R irradiated in chosen channels. The calculations were made based on irradiation channel values and the average values of the Carousel. The results of score point out that the -method is producing reliable results. From now on, the values of mass fractions in several matrices, the production and studies with radioisotopes will be more accurate and the activities calculated more precisely.

The measurement of uranium (U) isotope ratios in urine provides valuable information about the source of U exposure in humans and can be vitally important in a radiological emergency. This method provides rapid and accurate results for U/U at U concentrations as low as 0.42 ng/L, which is equivalent to ~200 ng/L of total U for a depleted U (DU) at a U/U ratio of ~0.002. The results are within 6% of Certified Reference Materials target values and agree with Department of Defense Armed Forces Institute of Pathology inter-laboratory comparison target values with a bias range of -6.9% to 7.6%.

Inductively coupled plasma mass spectrometry (ICP-MS) has proven to be an excellent analytical technique with high sensitivity for detecting low levels of long-lived radionuclides, such as thorium. However, the high-sensitivity technique increases the memory effect of thorium. This study developed a rapid, high-throughput, simple method for measuring thorium in urine using quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS). Replacing the commonly used hazardous hydrofluoric acid with a rinse solution of 0.025 mol/L oxalic acid and 5% (v/v) nitric acid eliminated the memory effect of thorium. U was used as internal standard in this study. The limit of detection (LOD) for thorium in this study is 0.77 ng/L, which is comparable to those of reported methods using more sophisticated and expensive sector field inductively coupled plasma mass spectrometry (SF-ICP-MS). This proposed method can determine thorium concentrations in urine in both occupationally exposed workers and populations that live in areas with high background levels of thorium.

A rapid analytical method for quantifying Sr in infant formula prior to secular equilibrium is presented. The approach is dependent on the use of two separations of Sr from Y, with the first providing an Y ingrowth start point and the second providing an Y ingrowth end point. Data were obtained at activity concentrations of approximately 6 Bq/kg and 160 Bq/kg, the latter of which is representative of the US Food and Drug Administration (FDA) Derived Intervention Levels (DIL). Experiments were designed to collect data from ingrowth periods ranging from 16 h to 2 weeks. Activities obtained with a separation interval as low as 16 h ranged from 92.7 to 109.4% of the known value. When Y ingrowth was allowed to occur for 24 h or longer, the activities ranged from 93.2 to 106.2% of the known value and the precision of this group improved from 5.2 to 3.1%. The limit of quantification (LOQ) was 0.5 Bq/kg using 250 g sample portions.

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.

The aim of this study was the development and analytically validation of a radioimmunoassay system for the measurement of the serum ferritin concentration as one of the laboratory biomarkers for infection by Covid-19. The main components of the system were prepared in our laboratories. The first component ferritin was extracted and purified from human spleen with high purity. The second component was the 125I-labelled ferritin tracer, prepared using Chloramine-T method. Furthermore anti-ferritin antibodies and ferritin standards were provided. The developed system is sensitive, precise, reproducible and. can be translated into a kit formulation suitable for measuring serum ferritin for the detection of Covid-19 in patients at low costs and high efficiency.

To effectively kill microorganisms on scrap facemasks (FMs) surface and provide new material for extracting uranium (U(VI)) from seawater, scrap FMs was treated by N capacitance coupled (CCP) plasma and modified with polyamidoxime (PAO). The obtained PAO/FMs was well characterized and applied as an adsorbent in the extraction of U(VI) from seawater. The effects of environmental conditions on the adsorption capability of PAO/FMs for U(VI) were briefly studied. Results showed that plasma technique can synchronously kill microorganisms and induce acrylonitrile (AN) polymerization on FMs surface. The prepared PAO/FMs presented excellent adsorption capability for U(VI). The experimental results highlighted the application of plasma technique in the management of scrap FMs, and PAO/FMs in the extraction of U(VI) from seawater.

Natural radioactivity concentrations in recent alluvial soils from swampy areas and Tertiary rocks from Jaintiapur were measured using gamma-ray spectrometer equipped with HPGe detector. The average radioactivity concentration of Ra, Th and K were 47 ± 6, 64 ± 5 and 762 ± 40 Bqkg in soils, whereas, 25 ± 2, 37 ± 4 and 884 ± 41 Bqkg in rock samples, respectively. Average radioactivity concentrations of studied soil and rock samples exceeded the world average except Ra for rocks. Radio-elemental ratios suggest that an oxic depositional environment with low uranium and high thorium content. Regarding radiological hazard indices, radium equivalent activities (Ra), external hazard index ( ) and internal hazard index ( ) was found to be below the world permissible limits. Whereas, absorbed dose rate (D), and annual effective dose equivalent (AEDE) averages exceeded the world admissible values. Statistical studies show that radioactivity for Ra and Th linked to a source enriched in radioactive minerals and K related to a different sources high in K enriched minerals.

Dietary supplements and agricultural byproducts were characterized by neutron activation analysis. The nutritional potential of supplements was evaluated according to alternative and commercial categories, using analysis of variance and cluster analysis, and recommended dietary intake for children. The results indicated statistically significant differences between both categories for the elements Cs, K, Na, and Rb. For the nutritional elements Ca, Co, Fe, K, Na, and Zn, the categories were similar in cluster analysis. The similarity between elemental profiles of alternative supplements and agricultural byproducts was calculated using a dissimilarity matrix, showing that rice and wheat are the predominant ingredients.

The main objective of the present publication was to assess the reduction of internal radioactive contamination with Tc among medical personnel of nuclear medicine facilities using generally available respiratory tract protection systems. During the current research project, four respiratory tract protection systems were tested by estimation of Tc activity levels in blood samples collected from medical personnel. Medical staff were equipped with a disposable surgical mask, a half mask with gas absorbers, a half mask with aerosol absorbers and a half mask with gas absorbers with added Petryanov filter. The presented results indicate that wearing only a disposable surgical mask may significantly reduce radioactive internal contamination among medical personnel and improve their safety in the workplace. The best results of reduced Tc concentration in the blood were achieved by the use of a half mask with gas absorbers with added Pertryanov filters and a half mask with aerosol absorbers, where the reduction factors were estimated at 90% and 80%, respectively. Respiratory tract protection systems should become standard equipment for medical personnel performing ventilation-perfusion SPECT lung scans.

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.

Micro-mapping of terrestrial gamma radiation dose (TGRD) at meter grid spacing in and around four urban homes in Miri City shows rates ranging from 70 to 150 nGy/h. Tiled surfaces (floors and walls) vary between properties and have a clear and significant influence on TGRD which is highest in kitchens, washrooms and toilets. Application of a single indoor value for annual effective dose (AED) may lead to underestimations of up to 30%. The AED is unlikely to exceed 0.8 mSv in homes of this type in Miri, which is within recommended guidelines.