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 137Cs 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 137Cs 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 137Cs concentrations in the fish from several Indonesian coasts were <MDA – 109.75 mBq kg−1. In contrast, the 137Cs concentrations in mollusk, crab and prawn were 10.65–38.78, 4.02 and 6.16 mBq kg−1, respectively. 134Cs was not detected in the seawater, sediments or biota. Thus, it was concluded that 137Cs on the eastern and western Indonesian coasts originated from global fallout.