Estimation of radiological impact of the activities of Olusosun Dump Site on workers and dwellers of Olusosun, in Lagos Southwest Nigeria

This study assessed the potential radiological risks associated with the activities on Olusosun dump site on workers and dwellers of Olusosun community. The activity concentrations of 238U, 232Th and 40K from of soil and water samples were determined using High-Purity Germanium (HPGe) detector. The background radiation level of Olusosun dump site was measured using a portable Geiger-Müller counter-Radeye B20 survey meter. The mean value of background radiation was 1.46 mSv/yr. This value is about 46% higher than the recommended reference level of 1.0 mSv/yr for the public. The mean activity concentrations of 238U, 232Th and 40K in the soil samples were 19.1 ± 3.2, 29.1 ± 4.4 and 171.5 ± 6.1 Bq/kg respectively which are about 45.4%, 35.3% and 59.2% lower than the world's average levels. For the water samples, the mean activity concentrations obtained for 238U, 232Th and 40K are 0.4 ± 0.4, 0.8 ± 0.2 and 0.8 ± 0.3 Bq/l respectively. These are about 99.9% and 20% lower than WHO reference levels for 238U and 232Th. The mean absorbed dose rate in air (D), Annual effective dose (AED) outdoor, Radium Equivalent (Req), External hazard index (Hex) internal hazard index (Hin) and Excess lifetime cancer risk (ELCR) from soil samples were 33.6 nGy/h, 41.0 μSv/yr, 73.1 Bq/kg and 0.2, 0.3 and $1.4\times{10}^{-4}$, respectively. Absorbed dose in air D, AED outdoor, Req, Hex, Hin and ELCR are 41.1%, 41.4%, 80.3%, 80%, 75% and 50% lower than their corresponding world's average and references. The estimated AEDw from ingestion of water is 148.9 ± 50.4 μSv/yr, this is about 49% higher than the WHO reference level of 100.0 μSv/y from ingestion of water. The radiological hazard indices estimated from soil samples do not indicate any potential risks to the users. The elevated background radiation level of the dump site, and AEDw from ingestion of water, however, suggest that the activities on Olusosun dump site pose potential radiological risks on workers on the site and the public from consumption of water from Olusosun community.

Distribution of Radionuclides and Radiological Health Assessment in Seih-Sidri Area, Southwestern Sinai

The current contribution goal is to measure the distribution of the radionuclide within the exposed rock units of southwestern Sinai, Seih-Sidri area, and assess the radiological risk. Gneisses, older granites, younger gabbro, younger granites, and post granitic dikes (pegmatites) are the main rock units copout in the target area. Radioactivity, as well as radiological implications, were investigated for forty-three samples from gneisses (seven hornblende biotite gneiss and seven biotite gneiss), older granites (fourteen samples), and younger granites (fifteen samples of syenogranites) using NaI (Tl) scintillation detector. External and internal hazard index (H_ex, H_in), internal and external level indices (Iα, Iγ), absorbed dose rates in the air (D), the annual effective dose equivalent (AED), radium equivalent activity (Ra_eq), annual gonadal dose (AGDE), excess lifetime cancer risk (ELCR), and the value of Upper Continental Core ²³²Th/²³⁸U mass fractions were determined from the obtained values of ²³⁸U, ²³²Th and ⁴⁰K for the examined rocks of Seih-Sidri area. The average ²³⁸U mg/kg in hornblende biotite gneiss and biotite gneiss, older granites, and syenogranites is 2.3, 2.1, 2.7, and 8.4 mg/kg, respectively, reflecting a relatively higher concentration of uranium content in syenogranites. The results suggest that using these materials may pose risks to one's radiological health.

Radiological Hazard Evaluation of Some Egyptian Magmatic Rocks Used as Ornamental Stone: Petrography and Natural Radioactivity

Magmatic rocks represent one of the most significant rocks due to their abundance, durability and appearance; they can be used as ornamental stones in the construction of dwellings. The current study is concerned with the detailed petrography and natural radioactivity of seven magmatic rocks. All are commercial granitic rocks and are identified as black Aswan, Nero Aswan, white Halayeb, Karnak, Verdi, red Hurghada and red Aswan. Their respective mineralogical compositions are classified as porpheritic granodiorite, granodiorite, tonalite, monzogranite, syenogranite, monzogranite and syenogranite. A total of nineteen samples were prepared from these seven rock types in order to assess their suitability as ornamental stones. Concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K radionuclides were measured using NaI (Tl) scintillation gamma-ray spectrometry. Among the studied magmatic rocks, white Halayeb had the lowest average values of ²²⁶Ra (15.7 Bq/kg), ²³²Th (4.71 Bq/kg) and ⁴⁰K (~292 Bq/kg), all below the UNSCEAR reported average world values or recommended reference limits. In contrast, the other granitic rocks have higher values than the recommended limit. Except for the absorbed dose rate, other radiological hazard parameters including radium equivalent activity, annual effective dose equivalent, external, and internal hazard indices reflect that the White Halyeb rocks are favorable for use as ornamental stone in the construction of luxurious and high-demand residential buildings.