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.     

Occupational exposure of phosphate mine workers: airborne radioactivity measurements and dose assessment

Under the Egyptian program for radiation safety and control, airborne radioactivity measurements and radiological dose assessment were conducted in some phosphate and uranium mines. Abu-Tartor mine is one of the biggest underground phosphate mines in Egypt. Airborne radioactivity, radon ((222)Rn) and its short-lived decay products (progenies) and thoron ((220)Rn), were measured in selected locations along the mine. The environmental gamma and workers dose equivalent rate (mSv/y) were measured inside and outside the mine using thermo-luminescence dosimeters (TLD). The results were presented and discussed. The calculated annual effective dose due to airborne radioactivity is the main source of occupational exposure and exceeding the maximum recommended level by ICRP-60 inside the mine tunnels. A number of recommendations are suggested to control the occupational exposures.     

Agricultural and non-agricultural settlements for drought-afflicted pastoralists in Somalia

The severe drought of 1973–1975 in Somalia had major impacts on pastoral populations, many of whom moved into specially established camps where food, water and medical assistance were provided by the government and international agencies. At the end of the drought it was decided to settle the remaining 120,000 people in six settlements, three of which were agricultural and three oriented towards fishing. This paper analyzes these settlements, with particular attention paid to agricultural systems, organization and socioeconomic characteristics. Some of the problems facing the settlements included their location, administrative structure and relative overemphasis on social services as opposed to development of production and income generating activities. It is shown that the socioeconomic viability of settlements would be enhanced if careful studies were undertaken beforehand and if a diversified development strategy were employed.     

Seasonal variations of particle number concentration and its relationship with PM2.5 mass concentration in industrial-residential airshed

Environmental Geochemistry and Health - The smaller particles that dominate the particle number concentration (PNC) in the ambient air only contribute to a small percentage of particulate matter...     

The impact of mucormycosis (black fungus) on SARS-CoV-2-infected patients: at a glance

Environmental Science and Pollution Research - The emergence of various diseases during the COVID-19 pandemic made health workers more attentive, and one of the new pathogens is the black fungus...     

A comparison of dust impacts on polycrystalline and monocrystalline solar photovoltaic performance: an outdoor experimental study

Environmental Science and Pollution Research - Solar cells are considered one of the most important and widespread solar applications in the world. However, the performance of the PV modules is...     

A comparative study of tea waste derived humic-like substances with lignite-derived humic substances on chemical composition,spectroscopic properties and biological activity

Environmental Science and Pollution Research - Emerging demand for humic substances escalated the short supply of coal-related resources from which humic substances are extracted in large...     

Leaching of rare earths from Abu Tartur (Egypt) phosphate rock with phosphoric acid

The leaching of rare earth elements (REEs) from Egyptian Abu Tartur phosphate rock using phosphoric acid has been examined and was subsequently optimized to better understand if such an approach could be industrially feasible. Preliminary experiments were performed to properly define the design of experiments. Afterward, 2⁴ full factorial design was implemented to optimize the leaching process. Optimum REEs leaching efficiency (96.7 ± 0.9%) was reached with the following conditions: phosphoric acid concentration of 30 wt.-% P₂O₅, liquid/solid ratio, mL/g, of 5:1, at 20 °C, and 120 min of leaching time. The apparent activation energy of the dissolution of REEs from phosphate rock using the phosphoric acid solution was -19.6 kJ/mol. D2EHPA was subsequently applied as an organic solvent for REEs separation from the acquired leach liquor. REEs stripping and precipitation were conducted, and finally, rare earth oxides with a purity of 88.4% were obtained. The leach liquor was further treated with concentrated sulfuric acid to recover the used phosphoric acid and produce gypsum with a purity of >95% at the same time. A flow diagram for this innovative cleaner production process was developed, and larger-scale experiments are proposed to further understand this promising approach to comprehensive phosphate rock processing.

     

Correction to: Effect of gervital in attenuating hepatotoxicity caused by methotrexate or azathioprine in adult albino rats

Environmental Science and Pollution Research -