MOHAMED EHAB AHMED FAKHERELDIN BAKR

06/08/2023

https://avestia.com/MCM2023_Proceedings/files/paper/MMME/MMME_133.pdf

MOHAMED EHAB AHMED FAKHERELDIN BAKR

24/03/2023

https://aip.scitation.org/doi/abs/10.1063/5.0120701

MOHAMED EHAB AHMED FAKHERELDIN BAKR

24/01/2023

https://www.mdpi.com/2071-1050/15/3/2165

MOHAMED EHAB AHMED FAKHERELDIN BAKR

Elsayed Salama, Mohamed Attallah, Hosam M. Saleh

16/10/2022

https://www.mdpi.com/2071-1050/14/20/13298

MOHAMED EHAB AHMED FAKHERELDIN BAKR

E. Salama, W. Ruehm

01/08/2018

For complete assessment of inhalation doses of radon and its progeny inside the three main ancient Egyptian tombs in Saqqara, seasonal radon concentrations have been measured by using a new electronic device that allows for measurement of real-time–resolved radon concentrations. Measurements were complemented by very fast measurements of thoron concentrations, which turned out to be low. Based on these measurements, annual residence time inside these tombs and the newest International Commission on Radiological Protection–recommended radon dose conversion coefficients or seasonal effective doses were calculated. The results indicate that workers receive highest annual effective doses of up to 140 mSv, which exceeds the annual limit of 20 mSv, whereas lower values up to 15 mSv are received by guides. In contrast, much lower doses were obtained for one-time visitors of the investigated tombs. The obtained results are somewhat different but still consistent with those previously obtained by means of fixed passive dose meters at some of the investigated places. This indicates that reasonable estimates of the effective dose of radon can be also obtained from short-term radon measurements carried out only twice a year (summer and winter season). Increasing the ventilation, minimizing the working times, etc., are highly recommended to reduce the annual effective dose.

MOHAMED EHAB AHMED FAKHERELDIN BAKR

S. U. El-Kameesy, E. Salama, S. Elfiki, W. Ruehm

01/03/2016

Many archaeological sites in Egypt are unique worldwide, such as ancient tombs and pyramids, because they document fundamental developments in human civilization that took place several thousands of years ago. For this reason, these sites are visited by numerous visitors every year. The present work is devoted to provide a pre-operational radiological baseline needed to quantify occupational radiation exposure at the famous Saqqara region in Cairo, Egypt. A hyperpure Ge detector has been used in the γ-ray spectrometric analysis while the (222)Rn concentration was measured using a portable radon monitor RTM 1688-2, SARAD. The mean specific activities of (226)Ra, (232)Th and (40)K in the samples collected from the interior walls of the Saqqara tombs were determined and found to show average values of 16, 8.5 and 45 Bq kg(-1), respectively. The concentration of radon was measured inside the tombs Serapeum, South tomb and the Zoser Pyramid (fifth level) and an associated average working level of 0.83 WL was obtained. In order to avoid the health hazards associated with the exposure to radon during the long period of work inside these tombs, proposed solutions are introduced.

MOHAMED EHAB AHMED FAKHERELDIN BAKR

S. U. El-Kameesy, E. Salama, S. Elfiki

01/06/2015

In the present work, radon concentrations in five selected tombs in the valley of kings, Luxor city, have been evaluated utilizing a portable radon monitor RTM 1688-2, SARAD. Additionally, specific radioactivity concentrations of the radionuclides 226Ra, 232Th and 40K in the samples taken from the selected tombs showing results lower than the average international radioactivity levels. Seasonal variations of radon concentration have been observed, with high summer average radon concentration values at the tomb of RAMESES II SONS (KV 5) of about 6365 ± 190 Bq.m-3for the tomb’s inner chamber and 5511 ± 276 Bq.m-3for the tomb’s middle chamber. The highest winter average radon concentration was observed at RAMESES VI tomb (KV9) with a value of 491 ± 16 Bq.m-3. The tour guides are found to expose to an average associated annual effective doses ranging from 0.360 to 14.592 mSv.y-1and the visitors from 0.001 to 0.029 mSv.y-1while the corresponding results for workers ranging from 3.455 to 140.081 mSv.y-1 which exceed the world lower recommended level (3-10 mSv.y-1). Accordingly, to avoid the health hazards associated with the exposure to radon during the long period of work inside these tombs, proposed solutions are introduced.

MOHAMED EHAB AHMED FAKHERELDIN BAKR

S. U. El-Kameesy, E. Salama, S. Elfiki1

01/05/2010