With the increased numbers of nuclear power plants constructed along the east coast of China, it is
important to know radioactive sources and transport pathways between land and sea, in order to better
understand the impact of these nuclear facilities to the marine environment. Two sediment cores
collected from the East China Sea dated to 1959e2010 were analyzed for long-lived radioactive 129I and
stable 127I. It was observed that 129I levels (129I/127I ratio of (15.0e75.0)
1012) were significantly
increased compared to the pre-nuclear value (129I/127I ¼ 1.5
1012). Some 129I peaks were observed in
layers of 1959, 1966, 1971 and 1976 (1977), corresponding to the atmospheric nuclear weapon tests at
Pacific Proving Grounds and Lop Nor. The high values of 129I after the late 1970s are attributed to the
releases from the European reprocessing plants. In addition to ocean current transport, the atmospheric
dispersion through the interaction of theWesterlies with East Asia monsoon is the important pathway of
large-scale transport of pollutants from high latitude West Europe to middle latitude East Asia. Riverine
input is the main transport pathway of radioactive pollutants released from Lop Nor to the East China Sea
through the atmospheric dispersion, deposition and runoff processes.