Environmental Radiocesium in Subarctic and Arctic Alaska Following Chernobyl

Abstract

ABSTRACT. Radiocesium ('34Cs and '37Cs) concentrations were measured in soil, plant and wildlife samples from subarctic to arctic Alaska. Concentrations of 13'Cs ranged from below detectable or low levels in whale and fish samples to as high as 242 Bqkg in lichen. For all potential human food items, the radiocesium concentrations measured in this study were below accepted permissible levels for human consumption. Chemobyl-derived radiocesium concentrations ranged from below detectable or low levels in all arctic samples (soil, sediment, lichen, whale, fish and caribou) to 32 Bqkg in subarctic moss. Therefore the distribution and subsequent deposition of Chemobyl-derived radiocesium appears to be variable but decreasing significantly from the Subarctic (Fairbanks) to the Arctic. The present data support the suggestion that Chemobyl-derived debris arrived from westem Canada into central Alaska and subsequently moved to the north (arctic) and to the west, decreasing in the quantity deposited as the debris transversed the state.

Distribution of 137Cs in a Low Arctic Ecosystem in West Greenland

“…Data from Greenland (Aarkrog and Lippert, 1965) also show a connection between 137 Cs deposition and precipitation, indicating a latitudinal trend, with a decrease in the deposition as the latitude increases. Baskaran et al (1991) reported that the Chernobyl deposition in Alaska decreases as the latitude increases. Thomas et al (1992) treated arctic terrestrial ecosystem contamination in general, and showed that the depositional pattern of 137 Cs in Canada is similar to the latitudinal trend of 137 Cs deposition in Alaska.…”

“…Because the main part of the deposition following the CNPP accident was subject to dispersion only through the lower part of the troposphere, the contamination was mainly local and regional (Persson et al, 1987). However, minor parts of the release from the accident reached arctic terrestrial environments of Canada and Alaska (Taylor et al, 1988;Baskaran et al, 1991;Thomas et al, 1992;France et al, 1993).…”

Anthropogenic radioactivity in the vicinity of the Bilibino nuclear power station, Chukotka, Russia1

“…These Alaskan cores were collected far from any source except 1960s-derived bomb fallout, and contain at most very small contributions from the Chernobyl' accident (Baskaran et al, 1991). This indicates that even in the immediate vicinity of the BNPS, atmospherically derived fallout of radionuclides from weapons testing during the early Cold War period is the primary source of the anthropogenic radionuclide burden in soils.…”

“…These researchers reported 137 Cs activities of up to 9200 Bq/kg dw in pine cones of Pinus pumila growing 4 km from the power station in [1989][1990], suggesting that the power plant was contributing radionuclide contaminants to the surrounding area. Comparable maximum 137 Cs activities in vegetation at the same latitude in Alaska are currently less than 200 Bq/kg dw, and are almost entirely attributable to fallout from the atmospheric nuclear weapons testing era (Baskaran et al 1991;Cooper et al, 1996).…”

Radionuclides in the Arctic seas from the former Soviet Union: Potential health and ecological risks

“…With a BCF of 0.1 m"/kg for the muscle of fish, marine mammals, and seabirds, the levels of 137Cs in muscle would range from about 0.2 to 1.4 Bq/kg for species collected during those years. For comparison, Baskaran et al (1991) reported a concentration of 0.57 Bq/kg in muscle tissue of a bowhead whale obtained from the Chukchi Sea in 1987. This value is close to the geometric mean of 0.53 Bq/kg calculated from the predicted range of '37Cs concentrations in muscle.…”