Jaber Aazami, Abbas Esmaili Sari , Nader Bahrami-Far, Mahmod Ghasempouri, Mohsen Jafar Nejad,
Volume 14, Issue 6 (1-2012)
Abstract
Background: Aquatic ecosystems pollution with heavy metals, especially mercury, has always been a major concern for aquatic organisms health. Hence this study not only described an innovative method for analyzing organic mercury compound, but also evaluated total and organic mercury concentrations in great cormorant and compared them with world health standards.
Materials and Methods: In this cross-sectional study, 18 great cormorants were randomly captured in March, 2009. Total and organic mercury of muscle, kidney, and liver tissues were analyzed by an advanced mercury analyzer made in the United States (Model Leco, AMA 254), and statistical analysis was done by Mann-Whitney U, and Kolmogrove-Smirnov tests.
Results: Mean accumulated total mercury in liver, kidney, and muscle tissues were 5.67, 3.59, and 2.26 mg kg -1 w.w., respectively and organic mercury formed 82, 79, and 58 % of the total mercury.
Conclusion: The levels of accumulated mercury in all tissues of great cormorant were more than the established limits by WHO, FAO, and EPA. These results can be a serious warning for consumers of these birds, especially vulnerable people.
Mohamad Javad Tahmasebi Birgani, Fatemeh Seif, Mohamad Reza Bayatiani, Mansour Zabihzadeh, Seyed Mohamad Hosseyni,
Volume 16, Issue 8 (11-2013)
Abstract
Background: In this research dosimetric parameters of mercury was investigated as a radiotherapy modulator and compared with cerrobend as a common beam attenuator material in most radiotherapy centers. Also several designs for mercury shielding system were evaluated.
Materials and Methods: In this experimental research transmission factor of different thicknesses of cerrobend and mercury at 6MV and 18MV photon beams was measured in order to investigate mercury as a beam modulator. Relative dosimetry was done with ionization chambers and then mercury modulating system for radiotherapy was designed with different cross sections.
Results: The result show that the transmission values increased with field size increment due to increased scatter contribution, for all cerrobend and mercury thicknesses at two energies. The procedure of mercury transmission factor is in agreement with cerrobend transmission factor. The second designed system with hexagonal cross section is in good agreement with patient contour.
Conclusion: The experimental investigation on mercury dosimetric parameters showed that mercury can be proposed as a modifier in radiotherapy because of its profit properties such as being liquid in room temperature, power of attenuation and …. So mercury can be proposed as a beam modifier (at closed system because of its poison vapor) in radiotherapy. Keywords: beam modifiers, Cerrobend, dosimetry, Mercury
