No abstract

Natural radioactivity concentrations due to the coal mining in Gabal El-Maghara, North Sinai, Egypt, were determined using gamma-ray spectroscopy. Coal, water and soil samples were investigated in this study. The (226)Ra, (232)Th and (40)K activity concentrations in coal before extraction were 18.5 +/- 0.5, 29.5 +/- 1.2 and 149.0 +/- 8.4 Bq kg(-1), respectively. These concentrations were reduced to 18-22% after extraction due to the clay removal of the coal ore. The activity contents of the water and soil samples collected from the surrounding area did not show any evidence of enhancement due to the mining activities. Absorbed dose rate and effective dose equivalent in the mine environment were 29.4 nGy h(-1) and 128.0 microSv a(-1), respectively. The measured activity concentrations in the mine environment and the surrounding areas (5 km away from the mine) are similar to that found in other regions in North and South Sinai. Based on the measurements of gamma-ray emitting radionuclides, the mine activity does not lead to any enhancement in the local area nor represents any human risk.

This study compares the external dose due to the gamma-ray emitting radionuclides in various areas in North Sinai, Egypt. The whole area was divided into 10 regions. The average absorbed dose rates were evaluated for each region. It was found that Zaranik-protected area and Al-Massaid have the highest values of 72.7 and 57.2 nGy h(-1), respectively. The corresponding values of the remaining regions were <23 nGy h(-1). The mean annual effective dose equivalents for the four largest cities Rafah, El-Sheikh Zuwaied, Al-Arish and Bir El-Abd were 20.8, 18.8, 57.4 and 14.0 microSv, respectively. The results are compared with those from different areas in Egypt and in various countries.

This work describes the concentrations of radioisotopes in soil, sediment, wild plants and groundwater in southwestern Sinai. The study area extends from Suez to Abu Rudies along the eastern part of the Suez Gulf. It included two hot springs: Ayun Musa and Hammam Faraoun. No dependence of ¹³⁷Cs concentrations on any of the measured sand characteristics was found, including calcium carbonate. The enrichment of ²²⁶Ra in Hammam Faraoun hot spring was the most prominent feature. The ²²⁶Ra concentration in hot springs of Ayun Musa and Hammam Faraoun were 68 and 2377 Bq kg⁻¹ for sediments, 3.5 and 54.0 Bq kg⁻¹ for wild plants and 205 and 1945 mBq l⁻¹ for the groundwater, respectively. In addition, ²²⁶Ra activity concentration in local sand in the area of Hammam Faraoun was ∼14 times that of Ayun Musa. On the other hand, the ²³²Th concentrations were comparable in the two hot springs, while ¹³⁷Cs concentrations were relatively higher in Ayun Musa. The characteristics and radioelements studies support possible suggestions that the waters in the two hot springs have different contributions of sea and groundwaters crossing different geological layers where the water-rock interaction takes place.