The presence of natural radioactivity and 137Cs in the South China Sea bordering peninsular Malaysia

Abstract

The presence of natural radioactivity and (137)Cs has been investigated in fresh media obtained from South China Sea locations off the coast of peninsular Malaysia. The media include seafood, sea water and sediment. The samples were collected some weeks prior to the devastating 2011 Tōhoku earthquake and associated tsunami, the occurrence of which precipitated the Fukushima incident. All samples showed the presence of naturally occurring (226)Ra, (228)Ra and primordial (40)K, all at typically prevailing levels. The concentrations of natural radioactivity in molluscs were found to be greater than that of other marine life studied herein, the total activity ranging from 337 to 393 Bq kg(-1) dry weight. The total activity in sea water ranged from 15 to 88 Bq l(-1). Sediment samples obtained at deep sea locations more than 20 km offshore further revealed the presence of (137)Cs. The activity of (137)Cs varied from ND to 0.5 Bq kg(-1) dry weight, the activity increasing with offshore distance and depth. The activity concentrations presented herein should be considered useful in assessing the impact of any future radiological contamination to the marine environment.

Assessment of Radiation and Heavy Metals Risk due to the Dietary Intake of Marine Fishes (Rastrelliger kanagurta) from the Straits of Malacca

“…are also known to enhance the naturally occurring radioactivity in the marine environment. In addition, there are anthropomorphic contributions from post-nuclear disposal of industrial and radioactive waste, underwater nuclear device tests, accidents including leaks from nuclear power plants and from reprocessing of spent nuclear fuel etc [2, 5–7]. …”

“…Marine animal has tendency to burrow down in the bottom sea sediments and rocks, filtering on organic particles and algae along with tiny fishes and planktons, which may lead to increase the uptake of radioactive and heavy metals) of radionuclides and toxic/heavy metals from their surroundings, not least fish and shell fish relative to other marine life (e.g., molluscs, crustaceans, and fishes) [2, 5, 14–19]. Seafood (e.g., molluscs, crustaceans, and fishes) and their products can typically be one of the major sources of protein to populations in coastline regions, including those around the Straits of Malacca, one of the most important shipping lanes in the world, transporting about one-quarter of the world's traded goods [2, 5, 14, 16, 20, 21]. Approximately three million barrels of crude oil are shipped through the Straits daily, subjecting the sensitive marine environment to the threat of accidental oil spillage; over the 10-year period 1981–199, an average of two to three oil spill incidents per year were recorded in these waters [21].…”

Measurement of Natural and Artificial Radioactivity in Infant Powdered Milk and Estimation of the Corresponding Annual Effective Dose

“…The calibration of the detector was done to take into account self-absorption. A detailed description of the measurement system and calibrations of the detector have been explained in Amin et al (2013). Meanwhile, the detector system has a cylindrical lead shielding arrangement (consisting of 10-cmthick lead internally lined with cadmium-copper coating), having a fixed bottom and a movable cover surrounding the detector to reduce background radiation.…”

Radiological Implications of Coal-Mining Activities in Maiganga Coalfield of North-Eastern Nigeria

“…1 Map of Gombe state, showing the project site (P-type coaxial ORTEC GEM-25 model). The detector arrangement was such that very thick cylindrical lead was used to shield the Ge crystal from external radiation interference (Amin et al 2013b 226 Ra, and 232 Th was calculated using the equation :…”