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Staff occupational radiation exposure is limited to 20 mSv annually to preclude tissue reaction and lower risk of cancer effect. Staff occupational exposure arises during the preparation, injection, and scanning of the patients. Recent studies reported that nuclear medicine personnel might exceed the annual dose limit in high workload and poor radiation protection circumstances. Therefore, an accurate estimation of the annual dose limit is recommended. The goal of this research is to calculate the cumulative external effective dose (mSv) per year for nuclear medicine physicians, technologists, and nurses at SPECT/CT department. A total of 15 staff worked in the nuclear medicine department at King Saud Medical City (KSMC), Riyadh, Saudi Arabia were evaluated for the last six years. 99mTc is used more frequently for most of the patients. The procedures include renal, cardiac scintigraphy procedures. Staff dose was quantified using calibrated thermoluminecnt dosimeters (TLD-100) with an automatic TLD reader (Harshaw 6600). Exposure to ionizing radiation was evaluated in terms of deep doses (Hp(10) were evaluated. The overall average and standard deviation of the external doses for nuclear medicine physicians, technologists' and nurses were 1.8 ± 0.7, 1.9 ± 0.6, 2.0 ± 0.9, 2.2 ± 0.8, 6.0 ± 2.8, and 3.6 ± 1.3 for the years 2015,2016,2017,2018,2019, and 2020, respectively. Technologists and nurses received higher doses of compared to the nuclear medicine physicians. Technologists and nurses involved in radionuclide preparation, patients' injection, and image acquisition. Staff annual exposure is below the annual dose limits; however, this external dose is considered high compared to the current workload. • Staff annual effective dose was estimated at nuclear medicine department equipped with two SPECT/CT systems. • External effective dose in terms of Hp(10) was monitored for six consecutive years. • Occupational exposure was quantified with thermoluminecnt dosimeters (TLD-100). • Technologists and nurses received higher doses than the nuclear medicine physicians. • Staff annual radiation from external exposure is 50% below the annual dose limits. [ABSTRACT FROM AUTHOR]

This work using a borosilicate glass medium seeks to detect photoneutrons generated by a medical linear accelerator. The studies involved an Elekta Infiniti accelerator located in the Oncology Centre, Medical City, Riyadh, the neutrons resulting from interactions at above-threshold therapeutic photon energies. The borosilicate detectors were produced from microscope glass slides of nominal thickness 1.0 mm, the latter made into square segments of area 0.6 × 0.6 cm2, a size capable of being accommodated within the planchette of the thermoluminescent (TLD) Reader (Harshaw 600). With some 4% boron in the coverslip glass and the abundance of 10B being 19.8%, thermalised neutrons 10B(n,α)7Li interactions offer a cross-section that can achieve a value as large as 3837 b. Apart from interactions in boron, of additional note is that 2H(γ,n)1H and 9Be(γ,n)8Be are two further photoneutron reactions, giving rise to particularly low threshold energies at 2.226 and 1.666 MeV, respectively. The presence of natural carbon in the present borosilicate samples has been measured to be 1.3%. Accordingly, with the abundance of 13C in natural carbon being 1.109% this would appear to be of very little interest herein. Moreover, compositional measurements made on the borosilicate coverslip glass indicates 9.40 Na. The induced activity in the glass falls to some 25% 30 h post-irradiation, a delay time beyond which readout can subsequently be conducted. • Borosilicate glass media for neutron sensing was developed. • Photoneutron was generated using an Elekta Infiniti linear accelerator beams. • Neutron activation of nuclides within the expanse of the beam should be considered. [ABSTRACT FROM AUTHOR]

The main objective of this study is to identify the atmospheric 7Be concentrations in 130 surface air samples collected from three stations located in Riyadh, Haql and Khafji cities in Saudi Arabia between November 2012 and April 2014. Monthly variations as well as seasonal patterns of 7Be were studied using a medium-volume air sampler and a gamma spectroscopy system equipped with a high-purity germanium (HPGe) detector. 7Be exhibited one maximum specific activity in summer and one minimum in winter with average monthly concentrations of 12.4 ± 0.9, 15.4 ± 1.2, and 18.0 ± 1.3 mBq m−3 in Riyadh, Haql and Khafji, respectively. Overall, the average 7Be concentration in the three stations was 12.9 ± 1.0 mBq m−3, whereas the maximum value of 29.5 mBq m−3 was registered in Khafji city in August 2013. Besides 7Be, measurements indicate observations of 40 K, 137Cs, 226Ra radionuclides in surface air samples collected from the three stations. 40 K showed measurable concentrations, whereas the concentrations of 137Cs and 226Ra were only detected in a limited number of samples. • 7Be were studied using a medium-volume air sampler and a gamma spectroscopy system. • The measurements were performed in three locations in Saudi Arabia. • 4 K showed measurable concentrations, whereas the concentrations of 137Cs and 226Ra were below the detection limit. • 7Be and 4 K radionuclides were affected by local atmospheric conditions. [ABSTRACT FROM AUTHOR]