Uranium bioassay and radioactive dust measurements at some uranium processing sites in Egypt--health effects

The safety of radiation workers in the uranium mining industry requires close and continuous monitoring of their working conditions. In this study, external radiation surveillance, radioactive dust monitoring and the bioassay of uranium were carried out in some processing sites. As dust represents one of the most important sources of radiation exposure in mills and mines, dust monitoring and bioassays were performed for a sample of workers on the production lines. The concentration of uranium in air ranged from 22.6 x 10(-7) to 11.1 x 10(-5) Bq cm-3, and the exposure levels ranged from 1 to 80 microSv h-1. Laser fluorimetric determination of uranium in urine samples showed concentrations in the range 8.4-29.2 micrograms L-1. Renal function parameters, such as serum creatinine and urea, and hematological parameters were determined in an attempt to correlate them with radiation exposure and the health status of the workers. Urine specimens collected from workers at the ore crushing and separation site showed elevated concentrations of uranium (up to 29.2 micrograms L-1) and a strong correlation between these concentrations and the registered serum creatinine. The mean uranium excretion in the investigated group was more than 20 times the occupational exposure decision level for urine uranium of 0.8 microgram L-1.     

Inhibition and recovery of serum,liver and brain acetylcholinesterase activities in rats exposed to new groups of O-ethyl phosphoramidates and benzo-1,3,2-dioxaphospholenes

Searching for new organophosphorus compounds with minimum effects on acetylcholinesterase of non-target organism especially mammals has gained an increased attention in the public concern. In this effort, the effects of some recently introduced O-ethyl phosphoramidates and benzo-1,3,2-dioxaphospholenes on rat acetylcholinesterase in different tissues have been evaluated in vivo and compared with the effects of fenitrothion, a commercial pesticide with reported moderate toxicity to mammals. The tested compounds were introduced orally in a single dose of 85?mg/kg body weight. Results indicated that the tested phosphoramidates lowered the enzyme activity to 54–69, 36–71 and 70–76% of its normal activity in serum, liver and brain, respectively. Meanwhile, the enzyme activity was depressed by fenitrothion to 11, 2 and 11% in the mentioned organs respectively. The lower anticholinesterase activity of the examined phosphoramidates than that of fenitrothion was attributed to their low hydrophobicity and low electrophilicity of their phosphorus atom, which reduces their interaction with the enzyme active site.     

Considerable hazards produced by heavy fuel oil in operating thermal power plant in Assiut, Egypt

Heavy fuel oil and ash samples were collected from the Assiut thermal power plant in Egypt and subjected to gamma spectrometry analysis for natural radioactivity contents. Considerable results were observed where the ash contains nearly 1,000 times natural radionuclides more than raw oil. The results were confirmed by measuring the samples via using different devices in different institutions. All ash samples had radium equivalent activities and external hazard index values more than 370 Bq/kg and unity respectively. The mean absorbed dose rate was10,650 nGy/h which is nearly 190 times higher than the global average value of 55 nGy/h. The corresponding annual external effective dose is estimated to be 13 mSv/year, which is nearly 30 times higher than that in areas of natural background radiation (0.46 mSv/year).     

Assessment of natural radioactivity levels in soil samples from some areas in Assiut, Egypt

The natural radioactivity of soil samples from Assiut city, Egypt, was studied. The activity concentrations of 28 samples were measured with a NaI(Tl) detector. The radioactivity concentrations of ²²⁶Ra, ²³²Th, and ⁴⁰K showed large variations, so the results were classified into two groups (A and B) to facilitate the interpretation of the results. Group A represents samples collected from different locations in Assiut and characterized by low activity concentrations with average values of 46.15?±?9.69, 30.57?±?4.90, and 553.14?±?23.19 for ²²⁶Ra, ²³²Th, and ⁴⁰K, respectively. Group B represents samples mainly collected from the area around Assiut Thermal Power Plant and characterized by very high activity concentrations with average values of 3,803?±?145, 1,782?±?98, and 1,377?±?78 for ²²⁶Ra, ²³²Th, and ⁴⁰K, respectively. In order to evaluate the radiological hazard of the natural radioactivity, the radium equivalent activity (Ra_eq), the absorbed dose rate (D), the annual effective dose rate (E), the external hazard index (H _ex), and the annual gonadal dose equivalent (AGDE) have been calculated and compared with the internationally approved values. For group A, the calculated averages of these parameters are in good agreement with the international recommended values except for the absorbed dose rate and the AGDE values which are slightly higher than the international recommended values. However, for group B, all obtained averages of these parameters are much higher by several orders of magnitude than the international recommended values. The present work provides a background of radioactivity concentrations in the soil of Assiut.     

Pharmacological implications of ipriflavone against environmental metal–induced neurodegeneration and dementia in rats

Environmental Science and Pollution Research - Long-term exposure to environmental neurotoxic metals is implicated in the induction of dementia and cognitive decline. The present study aims to...     

Influence of the presence of ruthenium on the activity and stability of Co–Mg–Al-based catalysts in CO2 reforming of methane for syngas production

Environmental Science and Pollution Research - Hydrogen production by methane dry reforming is an important yet challenging process. A performing catalyst will favor the thermodynamic equilibrium...     

Parent–offspring dietary segregation of Cory’s shearwaters breeding in contrasting environments

In pelagic seabirds, who often explore distant food resources, information is usually scarce on the level of trophic segregation between parents and their offspring. To investigate this issue, we used GPS tracking, stable isotopes and dietary information of Cory’s shearwaters Calonectris diomedea breeding in contrasting environments. Foraging trips at Selvagem Grande (an oceanic island) mainly targeted the distant African coast, while at Berlenga island (located on the continental shelf), shearwaters foraged mainly over nearby shelf waters. The degree of isotopic segregation between adults and chicks, based on δ¹³C, differed markedly between the two sites, indicating that adult birds at Selvagem fed their chicks with a mixture of shelf and offshore pelagic prey but assimilated more prey captured on coastal shelf waters. Isotopic differences between age classes at Berlenga were much smaller and may have resulted from limited dietary segregation or from age-related metabolic differences. The diet of shearwaters was also very different between the two colonies, with offshore pelagic prey only being detected at Selvagem Grande. Our findings suggest that spatial foraging constraints influence resource partitioning between pelagic seabirds and their offspring and can lead to a parent–offspring dietary segregation.     

Recent trends in treatment technologies of emerging contaminants

In the recent years a group of contaminants, known collectively as emerging contaminants (ECs), have attracted considerable attention due to their widespread in the environment, and lack of knowledge on their impacts on ecosystem and human health. This review gives an overview on the sources, impacts, and conventional treatment technologies of ECs and an in-depth review of the literature on the state-of-the-art treatment technologies and their performance in the removal of ECs from water sources and drinking water. A careful statistical analysis of the number of publications on the different treatment technologies of ECs was performed to identify the hot spots in this research area. Conventional treatment technologies are not able to remove ECs sufficiently. The discharge of raw or partially treated wastewater is the main source of ECs in the environment. The research in recent years is focusing on using advanced treatment process (AOPs), followed by adsorption and membrane technologies. From a technical point of view, AOPs surpass other treatment technologies as they can completely eradicate ECs without the generation of side products. Developing efficient, green, and cost-effective materials to be used as adsorbents, photocatalysts, membranes, or membrane fillers, is one of the main research trends nowadays. Combined AOPs based on exploiting solar light, ultrasound and electrochemistry are gaining growing interest and show high potential for the treatment of ECs.     

Determination of etoxazole residues in fruits and vegetables by SPE clean-up and HPLC-DAD

A method for determination of etoxazole residues in apples, strawberries and green beans was developed and validated. The analyte was extracted with acetonitrile from foodstuff and a charcoal-celite cartridge was used for clean-up of raw extracts. Reversed phase high performance liquid chromatography with photodiode array detector (HPLC-DAD) was used for the determination and quantification of etoxazole residues in the studied samples. The calibration graphs of etoxazole in a solvent or three blank matrixes were linear within the tested intervals 0.01–2 mg L^?1, with correlation coefficient of determination >0.999. The combined solid phase extraction (SPE) clean-up and the chromatographic method steps were sensitive and reliable for simultaneous determination of etoxazole residues in the studied samples. The average recoveries of etoxazole in the tested foodstuffs were between 93.4 to 102% at spiking levels of 0.01, 0.10, and 0.50 mg kg^?1, with relative standard deviations ranging from 2.8 to 4.7%, in agreement with directives for method validation in residue analyses. The limit of detection (LOD) of the HPLC-DAD system was 100 pg. The limit of quantification of the entire method was 0.01 mg kg^?1.     

Radiological study of exposure levels in El Maghara underground coal mine

Coal is largely composed of organic matter, but it is the inorganic matter in coal minerals and trace elements that have been cited as possible causes of health, environmental and technological problems associated with the use of coal. Some trace elements in coal are naturally radioactive. These radioactive elements include uranium (U), thorium (Th) and their numerous decay products, including radium (Ra) and radon (Rn). Although these elements are less chemically toxic than other coal constituents, such as arsenic, selenium or mercury, questions have been raised concerning the possible risk from radiation. In order to accurately address these questions and to predict the mobility of radioactive elements during the coal fuel cycle, it is important to determine the specific activity, distribution and form of radioactive elements in coal. The assessment of the radiation exposure from coal burning is critically dependent on the specific activity of radioactive elements in coal and in the fly ash that remains after combustion. The El-Maghara coal mine is the only producing coal mine in Egypt. It is located in the middle of the Sinai desert about 250 km north-east of Cairo, where a coal-fired power plant is intended to be built. In this study, a pre-operational radiological baseline of the site and the occupational radiation exposures due to radon progeny in the mine were determined. The specific activities of 226Ra, 232Th and 40K in soil and coal dust samples collected along the main gallery ranges were found to be 6-22.9, 9.6-47.3 and 77-489 Bq kg-1, respectively. Soil samples collected around the mine showed concentrations of 226Ra, 232Th and 40K in the ranges 2.7-20.2, 3.2-12.6 and 14.6-201 Bq kg-1, respectively. All of the mean values of radon progeny were lower than the action levels for working places recommended in the International Commission on Radiological Protection (ICRP) 65.