Distribution of 226Ra–210Pb–210Po in marine biota and surface sediments of the Red Sea, Sudan

Radioactivity concentrations and their radiological significance in sediments of the Tema Harbour (Greater Accra, Ghana)

“…Apart from the 210 Pb levels in phytoplankton, the radioactivity levels in all the reference organisms were generally low compared to the levels in the sediments. This indicates that the radionuclides associate mainly with the sediments, despite their potential for bioaccumulation (Hassona et al, 2008;Sirelkhatim et al, 2008). This supports the view that sediments are the major sinks for radionuclides in aquatic ecosystems (Sugandhi et al, 2014).…”

“…The sealed samples were then counted for 2e3 days, and activities measured for 210 Pb at 46.5 keV, 214 Pb at 352 keV, 212 Pb at 239 keV, 208 Tl at 583 KeV, 228 Ac at 338 and 911.0 keV, 234 Th at 63.3 and 92.5 keV, 40 K at 1460 keV and 137 Cs at 662 keV. The measured activities were decay-corrected with respect to the date of sediment sampling (Sirelkhatim et al, 2008) and associated errors were determined from l-sigma counting statistics (Nyarko et al, 2011). The activity of 228 Th was obtained from the activity of its daughter 212 Pb radionuclide and The average activity of 228 Ac and 212 Pb was used as a proxy for 232 Th activity.…”

“…The origin of the excess 210 Pb found in sediments is well known, and it is the basis of the 210 Pb-based radiometric method for dating recent sediments (Mabit et al, 2014). On the contrary, the observed disequilibria between 238 U (derived from 234 Th activity, see Section 2.3) and 226 Ra may be ascribed to differences in geochemical behaviour of the radionuclides (Koide et al, 1973 Ra and 238 U are less particle-reactive than Th isotopes with greater tendency to diffuse from sediments into the surrounding seawater (Chen & Huh, 1999;Sirelkhatim et al, 2008;Sugandhi et al, 2014). The higher levels of 238 U relative to 226 Ra in the sediments may be due to diffusion and loss of Ra from sediment owing to its higher solubility in seawater or higher leachability of 226 Ra from the harbour sediments than 238 U- 234 Th.…”

Assessment of 210Po and 210Pb in marine biota of the Mallipattinam ecosystem of Tamil Nadu, India

“…Taken together, it is clear that Mallipattinam coastal water does not possess high activity of 210 Po and 210 Pb. In sediment, our 210 Po and 210 Pb activities (Table 1) were less than those of other sites, including Kalpakkam (Iyengar, 1983), the Red Sea (Sirelkhatim et al, 2008), the Bay of Ghazaouet on the Algerian coast (Noureddine and Baggoura, 1997), and the Bay of Bengal (Sharif et al, 1994).…”

Determinação de isótopos de Urânio e Tório e Polônio em perfis de sedimento da Baixada Santista, SP

“…Existe um interesse cada vez maior no estudo dos ambientes marinhos e na determinação e quantificação de contaminantes provenientes das atividades antrópicas. Em particular, há interesse na determinação de radionuclídeos, tendo em vista aspectos relativos à radioproteção e aos efeitos ecotoxicológicos (Sirelkhatim et al, 2008).…”