Ho Manh Dung

Personal dose equivalents Hp(3) in interventional cardiology personnel are of growing regulatory concern following International Commission on Radiological Protection (ICRP) Publication 118, which revised the occupational eye lens dose limit to 20 mSv/year. This prospective cohort study presents the first peer-reviewed direct Hp(3) dosimetry data from Vietnamese catheterization laboratory workers. Twelve personnel (eight physicians, four technicians) were monitored over 10 weeks (202 procedures, Siemens Artis Zee system), with doses extrapolated to 12 weeks. Direct Hp(3) ranged from 0.58–4.59 mSv (physicians) and 0.26–1.01 mSv (technicians); annualized projections reached 19.10 mSv/year, approaching the ICRP limit. Five physicians exceeded the 6 mSv/year International Radiation Protection Association investigation level. Indirect dosimetry (Swiss Society of Radiobiology and Medical Physics-SSRPM two-dosemeter algorithm) overestimated direct measurements by mean factors of 1.31 (physicians) and 1.68 (technicians). A strong dose–fluoroscopy time correlation was identified for physicians (R2 = 0.918). Direct Hp(3) monitoring and lead-equivalent eye protection are recommended.

A five-year (2018-2022) monitoring programme of naturally occurring radioactive material (NORM) was implemented in Ho Chi Minh City (HCMC; population ~9.3 million) to establish the first measurement-based environmental radioactivity baseline for a Vietnamese megacity. Atmospheric aerosol, surface soil, surface water, and indoor 222Rn were investigated at eight spatially representative stations. Activity concentrations were determined using high-purity germanium (HPGe) gamma-ray spectrometry, gas-flow proportional alpha/beta counting, CR-39 solid-state nuclear track detectors, and RAD7 continuous radon spectrometry under harmonised quality assurance protocols. Aerosol radionuclide concentrations remained temporally invariant over the monitoring period (Kruskal-Wallis, p>0.10), with mean activities of 0.15-0.20 µBq m-3 (238U), 0.16-0.19 µBq m-3 (232Th), and 0.11-0.12 µBq m-3 (40K). Soil activities showed significant inter-district variability (p<0.05), ranging from 19.9-48.3 Bq kg-1 (238U), 28.1-66.5 Bq kg-1 (232Th), and 227-509 Bq kg-1 (40K), consistent with sedimentary provenance rather than anthropogenic inputs. Gross beta activity concentrations in Saigon River water (0.159-0.187 Bq L-1) and Tan Quy Dong wastewater treatment plant influent (0.419 ± 0.015 Bq L-1) were below the WHO screening level (1 Bq L-1). Indoor 222Rn concentrations exhibited a geometric mean of 23 Bq m-3, corresponding to annual effective doses of 0.54-0.82 mSv y-1. Radiological indices (Raeq: 117.4-150.8 Bq kg-1; ELCR: 0.235-0.296 × 10-3) indicate low radiological risk relative to regional urban environments. No anthropogenic radionuclides were detected. The dataset provides a reference baseline supporting UNSCEAR reporting and future environmental impact assessments associated with Vietnam’s nuclear energy development.

Edible Bird’s Nest (EBN) is a highly prized food product, making it a frequent target for economic adulteration. Consequently, robust quality assurance is paramount to protect consumers and ensure market integrity. A significant barrier to effective quality control, however, is an incomplete understanding of the natural chemical variability within authentic EBN. This variability, influenced by factors such as geographical origin, bird species, and post-harvest processing, can confound analytical measurements and complicate the definition of a standard reference. This study provides an existence proof in a defined cohort, characterizing microscale chemical heterogeneity in authentic A. fuciphagus EBN. We employed a multi-modal Fourier Transform Infrared (FTIR) spectroscopy approach, integrating transmission, macro-attenuated total reflectance (ATR), and high-resolution micro-ATR chemical imaging. A diverse set of validated, authentic EBN samples was analyzed using unsupervised Principal Component Analysis (PCA) to explore the data structure. Our results reveal significant and previously unquantified spectral heterogeneity, particularly in protein and glycoprotein-related regions. In our cohort, the chemical signatures of authentic EBN do not collapse to a single, uniform profile but span a broad, multi-dimensional continuum. This inherent variability presents a critical challenge for conventional quality control methods that rely on simplistic, single-spectrum standards, which may lead to the misclassification of genuine products. By establishing a robust chemical baseline for the authentic class, this work provides the foundational data essential for developing next-generation authentication models capable of reliably distinguishing this natural variance from deliberate adulteration.

An optimized k0-standardized neutron activation analysis method incorporating cyclic irradiations (k0-CNAA) for short-lived radionuclides (SLRNs) has been developed at the Dalat research reactor. This paper highlights precise reactor parameter characterization using a cyclic irradiation system, simple sample preparation, and advanced calibration of HPGe detector-based gamma-ray spectrometry for SLRNs’ rapid multielement determination. By targeting SLRNs such as 77mSe, 110Ag, 20F, 179mHf, 52V, and 46mSc, with half-lives from seconds to minutes, the method enables quantification of elements essential for biological and environmental research. The in-house developed “k0-Dalat” software, featuring high automation, supports complete analysis. Method accuracy was validated using certified reference materials (SMELS-I, NIST-SRM-1566b, NIST-SRM-2711a), achieving deviations under 8% from certified values. Detection limits ranged from 0.1 to 1.9 mg/kg for target elements in biological samples, confirming the method’s high sensitivity and suitability for similar matrices.

Nanoparticles, due to their extensive production and application, can have significant consequences for the environment, including soil and plant pollution. Therefore, it is very important to assess how nanoparticles will affect plants depending on the exposure pathways. The effect of gold nanoparticles in a concentration range of 1–100 mg/L on Mentha spicata L. during a 28-day experiment was investigated. Two routes of nanoparticles exposure were applied: root and foliar. Transmission electron microscopy was used to characterize nanoparticles and their effect on plant leaves’ ultrastructure. Gold content in soil and plant segments was determined using k0-neutron activation analysis. For root exposure, gold was mainly accumulated in soil (15.2–1769 mg/kg) followed by root systems (2.99–454 mg/kg). The maximum accumulation of gold in leaves (5.49 mg/kg) was attained at a nanoparticle concentration of 100 mg/L. Foliar exposure resulted in the maximum uptake of gold in leaves (552 mg/kg) and stems (18.4 mg/kg) at the highest applied nanoparticle concentration. The effect of nanoparticles on the Mentha spicata L. leaves’ biochemical composition was assessed. Nanoparticles affected the content of chlorophyll and carotenoids and led to an increase in antioxidant activity. Root exposure to gold nanoparticles resulted in an increase in the number of starch grains in chloroplasts and also suppressed the activity of the soil microbiota. Gold extraction from mint leaves into herbal infusion varied from 2 to 90% depending on the concentration of nanoparticles in the solution and the exposure route. The health risk as a result of gold exposure via herbal tea intake was assessed through estimated daily intake. The hazard quotient values were found to be less than the cutoff, indicating that a cup of tea infusion should not cause a serious impact to human health.