NORM activity concentration in sediment cores from the Peninsular Malaysia East Coast Exclusive Economic Zone

Natural radioactivity and its radiological implications from soils and rocks in Jaintiapur area, North-east Bangladesh

Natural radioactivity concentrations in recent alluvial soils from swampy areas and Tertiary rocks from Jaintiapur were measured using gamma-ray spectrometer equipped with HPGe detector. The average radioactivity concentration of ²²⁶Ra, ²³²Th and ⁴⁰K were 47 ± 6, 64 ± 5 and 762 ± 40 Bqkg⁻¹ in soils, whereas, 25 ± 2, 37 ± 4 and 884 ± 41 Bqkg⁻¹ in rock samples, respectively. Average radioactivity concentrations of studied soil and rock samples exceeded the world average except ²²⁶Ra for rocks. Radio-elemental ratios suggest that an oxic depositional environment with low uranium and high thorium content. Regarding radiological hazard indices, radium equivalent activities (Ra_eq), external hazard index (H_ex) and internal hazard index (H_in) was found to be below the world permissible limits. Whereas, absorbed dose rate (D), and annual effective dose equivalent (AEDE) averages exceeded the world admissible values. Statistical studies show that radioactivity for ²²⁶Ra and ²³²Th linked to a source enriched in radioactive minerals and ⁴⁰K related to a different sources high in K enriched minerals.

An extended assessment of natural radioactivity in the sediments of the mid-region of the Egyptian Red Sea coast

In this study, nearly 84 marine sediment samples were collected from twelve points in four cities (Quseir, Safaga, Hurghada, and Ras Gharib) along the Egyptian Red Sea sectors. The collected samples were extensively examined to estimate the natural radioactivity level. The obtained results were compared to the reported ranges from other locations in different countries. Hazardous radiation parameters such as radium equivalent, annual dose, and external hazards were estimated and compared to United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) recommended levels. The values were recorded in the first natural radioactivity database of coastal sediments from Egyptian Red Sea cities. The dose rate for certain organs was evaluated. The results showed that Red Sea beach sediments are safe in terms of natural radioactivity. It can be concluded that they do not pose a risk to tourists going to the beaches for recreation or to sailors and fishers involved in economic activities along the Egyptian Red Sea coast.

Elevated levels of radium-226 and radium-228 in marine sediments of the Norwegian Trench ("Norskrenna") and Skagerrak

Oil and gas extraction activities discharge waters bearing radium isotopes which may potentially be transported to locations distant from the discharge point. Sediment cores from the Norwegian Trench and Skagerrak, potential sinks for North Sea discharges, were analyzed for the contents of these isotopes. All cores were such that data could be obtained from periods prior to and during extensive operations in the North Sea. Results indicate elevated levels of radium isotopes in upper sedimentary layers when compared to data for the Baltic Sea and Kattegat. Although diagenetic processes involving manganese cycling may be responsible for these enrichments, the data support previous work indicating a possible influence of North Sea discharges on sediments of the area. The results highlight the need for further work on elaborating background levels of these isotopes in the North Sea and related areas such that possible impacts of these discharges can be properly evaluated.