Simultaneous Determination of Uranium and Depleted Uranium Isotopic Ratio Using Inductively Coupled Mass Spectrometry

The Department of Veterans' Affairs Depleted Uranium Cohort in the Time of COVID-19: Translating a Traditional Surveillance Protocol to a Telehealth Platform

OBJECTIVE

In 2021, 37 members of a cohort of depleted uranium-exposed Gulf War I veterans were evaluated using a protocol tailored to accommodate COVID-19 safety practices on a telehealth platform.

METHODS

Individual elements of the legacy protocol were reviewed for urgency and feasibility of inclusion in a modified, telehealth platform.

RESULTS

The redesigned protocol included a participant readiness for telehealth assessment, nurse and physician telehealth visits, collection of usual health questionnaires, and urine collections for exposure monitoring for uranium and other fragment-related metal measures.

CONCLUSIONS

Despite some limitations in scope, the telehealth platform permitted a visual "visit" with surveillance participants who expressed a high comfort level with the format. The telehealth platform has apparent utility for occupational surveillance and should be explored as a standard approach for surveillance outside of public health emergencies.

Ultrasensitive detection of UO2 2+ based on dopamine-functionalized MoOx quantum dots

Uranium is an important nuclear fuel and the risk of human exposure to uranium increases as increasing amounts of uranium-containing waste enter the environment due to the rapid growth of nuclear power. Therefore, rapid, sensitive, and portable uranium detection is a promising approach to effectively control and monitor uranium contamination. To achieve this goal, abundant oxygen- and nitrogen-containing groups were introduced to molybdenum oxide quantum dot (MoO_x QDs) surfaces with dopamine (DA) modification. Due to the excellent coordination ability of oxygen- and nitrogen-containing groups with uranium, the obtained DA-functionalized MoO_x QDs (DA-MoOx QDs) showed a strong binding affinity for uranium and sensitivity was increased nearly 1000-fold compared with MoO_x QDs alone. The limit of detection was 3.85 nM, which is higher than most of the reported nanomaterials. Moreover, the DA-MoOx QD-based method showed high selectivity and uranium could be clearly detected under masking with ethylenediaminetetraacetic acid even when the concentration of other metal ions was 100-fold higher than that of uranium, showing a very promising method for uranium contamination control and monitoring.

A novel liquid crystal sensing platform for highly selective UO22+ detection based on a UO22+-specific DNAzyme

A label-free and selective sensor was established for uranyl ion (UO₂²⁺) detection based on a UO₂²⁺-dependent DNAzyme and liquid crystals (LCs). In the presence of UO₂²⁺, the substrate chains can be cleaved at the rA site by the DNAzyme strands. The cleaved products released from the DNAzyme strand will hybridize with the capture probes that are fixed on the LC sensing substrate to form double strands. The formation of double strands would disturb the original orientation and induce the rearrangement of liquid crystal molecules, resulting in the polarization images changing from uniform black to bright. Attributed to the specificity of the DNAzyme and the optical signal of the LC, a highly selective and label-free method was established with a detection limit of 25 nM. This approach showed satisfactory analytical performance and offered an inspiring platform for detecting other radioactive elements.

Urine miRNAs as potential biomarkers for systemic reactions induced by exposure to embedded metal

Aim: Explore the potential of urine microRNAs as biomarkers that may reflect the biological responses to pure metals embedded in skeletal muscle over time. Materials & methods: We tested a panel of military-relevant metals embedded in the gastrocnemius muscles of 3-month-old, male, Sprague-Dawley rats (n = 8/group) for a duration of 1, 3, 6 and 12 months, and performed small RNA-sequencing on the urine samples. Results: Results provide potential tissue targets affected by metal exposure and a list of unique or common urine microRNA biomarkers indicative of exposure to various metals, highlighting a complex systemic response. Conclusion: We have identified a panel of miRNAs as potential urine biomarkers to reflect the complex systemic response to embedded metal exposure.

Surveillance of Depleted Uranium-exposed Gulf War Veterans: More Evidence for Bone Effects

ABSTRACT

Gulf War I veterans who were victims of depleted uranium (DU) "friendly-fire" incidents have undergone longitudinal health surveillance since 1994. During the spring of 2019, 36 members of the cohort were evaluated with a monitoring protocol including exposure assessment for total and isotopic uranium concentrations in urine and a comprehensive review of health outcomes, including measures of bone metabolism and bone mineral density (BMD) determination. Elevated urine U concentrations were observed in cohort members with retained depleted uranium (DU) shrapnel fragments. In addition, a measure of bone resorption, N-telopeptide, showed a statistically significant increase in those in the high DU subgroup, a finding consistent with a statistically significant decrease in bone mass also observed in this high DU subgroup compared to the low DU subgroup. After more than 25 y since first exposure to DU, an aging cohort of military veterans continues to show few U-related health effects in known target organs of U toxicity. The new finding of impaired BMD in the high DU subgroup has now been detected in two consecutive surveillance visits. While this is a biologically plausible uranium effect, it is not reflected in other measures of bone metabolism in the full cohort, which have largely been within normal limits. However, ongoing accrual of the U burden from fragment absorption over time and the effect of aging further impairing BMD suggest the need for future surveillance assessments of this cohort.