Heny Suseno

Monitoring 137Cs and 134Cs at marine coasts in Indonesia between 2011 and 2013

Environmental samples (seawater, sediments and biota) were collected along the eastern and western Indonesian coasts between 2011 and 2013 to anticipate the possible impacts of the Fukushima radioactive releases in Indonesia. On the eastern coasts (south and north Sulawesi), the (137)Cs concentrations in the seawater and sediments were 0.12-0.32 Bq m(-3) and 0.10-1.03 Bq kg(-1), respectively. On the western coasts (West Sumatra, Bangka Island, North Java, South Java and Madura island), the (137)Cs concentrations in the seawater and sediments were 0.12-0.66 Bq m(-3) and 0.19-1.64 Bq kg(-1), respectively. In general, the (137)Cs concentrations in the fish from several Indonesian coasts were <MDA - 109.75 mBq kg(-1). In contrast, the (137)Cs concentrations in mollusk, crab and prawn were 10.65-38.78, 4.02 and 6.16 mBq kg(-1), respectively. (134)Cs was not detected in the seawater, sediments or biota. Thus, it was concluded that (137)Cs on the eastern and western Indonesian coasts originated from global fallout.

Radiocesium monitoring in Indonesian waters of the Indian Ocean after the Fukushima nuclear accident.

As data on anthropogenic radionuclide concentrations (i.e., (134)Cs and (137)Cs) in Indonesian marine environments including the Indian Ocean are scarce, offshore monitoring has been performed in the West Sumatra and South Java Seas. The activity concentration of (137)Cs ranges from below minimum detectable activity (MDA) to 0.13Bqm(-3) in the surface seawater of the South Java Sea and from lower than MDA to 0.28Bqm(-3) in the surface seawater of the West Sumatra Sea. The concentrations of (137)Cs in the surface seawater of the West Sumatra and South Java Seas are lower than the estimation of (137)Cs concentration in the subsurface waters owing to the input of the North Pacific Ocean via the Indonesian Throughflow (ITF). The concentrations of (134)Cs in the sampling locations were lower than MDA. These results have indicated that these Indonesian marine waters have not yet been influenced by the Fukushima radioactive release.

Bioaccumulation and retention kinetics of cesium in the Milkfish Chanos chanos from Jakarta Bay

Laboratory radiotracer experiments were conducted to study the uptake, assimilation, and retention of cesium (137Cs) in milkfish (Chanos chanos) from Jakarta Bay. In this study, we have examined the bioaccumulation and distribution of 137Cs in C. chanos obtained from 137Cs-labeled seawater and 137Cs-labeled Artemia sp. feeding. The uptake of 137Cs via seawater displayed a one-compartment model suggesting that the concentration factors of 137Cs within the milkfish (weight 2.46–9.86 g) at a steady-state period were between 10.66 and 3.98 mL g−1 after 10 days of exposure. The depuration ratewas observed to be low, with only 22.80–49.14% of 137Cs absorbed by C. chanos, which was absent 6 days after exposure. By contrast, depuration occurred quickly for radiolabeled food uptake, reaching 20% of retention within 10 days after exposure.Muscles and viscera of themilkfish exhibited the highest degree of end uptake and end depuration of 137Cs from seawater and feeding. © 2016 Elsevier Ltd. All rights reserved.

Present status of 137 Cs in seawaters of the Lombok Strait and the Flores Sea at the Indonesia Through Flow (ITF) following the Fukushima accident

Due to thermocline and surface water from the western equatorial Pacific Ocean, which are transported to the Indian Ocean, Indonesian marine waters play an important role in the global ocean circulation. The objective of this study was to assess the spatial distribution of 137Cs in the Lombok Strait as part of a national monitoring program concerning the possible impacts of radionuclides released as a result of the Fukushima accident. Sampling was conducted in the Flores sea and Lombok Strait on 15 to 24 November 2013. Measurements for the Lombok strait showed that 137Cs concentrations at surface layer, thermocline layer and 1000m depth were 0.27Bqm-3; 0.42Bqm-3 and <MDA (0.01Bqm-3), respectively. The water concentration of 134Cs at all monitoring stations were under MDA (0.01Bqm-3). The results the study indicate that the radiocesium input was from global fallout.