title: Measurements of cesium in Arctic beluga and caribou before and after the Fukushima accident of 2011.
abstract: Concern from northern communities following the Fukushima Daiichi nuclear accident of March 2011 has prompted a reassessment of the safety of their traditional foods with respect to radioactivity levels. To this end, a study was conducted to measure the levels of radionuclides in Arctic caribou (Rangifer tarandus) and beluga (Delphinapterus leucas). The main radionuclide of concern is cesium-137, which is easily transferred through the lichen-caribou food chain. Previous studies have been conducted on the cesium-137 levels in Canadian caribou herds from 1958 to 2000, allowing researchers to determine the amount of cesium-137 in caribou specifically attributable to atmospheric weapons testing and the Chernobyl nuclear accident in 1986. In this study, samples of lichens, mushrooms, caribou, beluga and beluga prey collected before and after the Fukushima accident were analyzed for radioactivity levels. Samples were processed and measured using gamma ray spectroscopy to identify the radionuclides present and determine the radioactivity concentration. Both calibration standards and Monte Carlo simulations were used to determine the efficiency of the detectors for the samples, taking into account differences in individual sample sizes as well as matrices. In particular, a careful analysis of the atomic composition of lichens and mushrooms was performed to ensure the efficiencies for these sample types were correct. A comparison of the concentrations from before and after the accident indicated that there was no increase in radioactivity as a result of the atmospheric plume from the Fukushima accident. Some cesium-137, likely attributable to fallout from atmospheric weapons testing of the 1950s and 1960s (since there was no cesium-134 measured in the samples), was measured in the post Fukushima caribou and beluga whale samples; however, this amount was determined to be insignificant for any radiological concern (9.1 ± 1.8 and 0.63 ± 0.23 Bq kg-1ww respectively). The activity concentrations of cesium-137 was about 200 times smaller than that of natural radioactive potassium in the beluga samples. Both the caribou and beluga results showed that these foods continue to be a healthy food choice for northern Canadians with respect to radioactivity, and this result has been communicated to the nearby northern communities and stakeholders.
authors.affiliation: Radiation Protection Bureau, 775 Brookfield Rd, A.L. 6302D, Ottawa, ON, K1A 1C1, Canada. Electronic address: Trevor.Stocki@canada.ca.
authors.forename: T J
authors.initials: TJ
authors.lastname: Stocki
authors.affiliation: Gamberg Consulting, 708 Jarvis St. Whitehorse, YT, Y1A 2J2, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Gamberg
authors.affiliation: Freshwater Institute Fisheries and Oceans Canada, 501 University Cres, Winnipeg, MB, R3T 2N6, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Loseto
authors.affiliation: Radiation Protection Bureau, 775 Brookfield Rd, A.L. 6302D, Ottawa, ON, K1A 1C1, Canada.
authors.forename: E
authors.initials: E
authors.lastname: Pellerin
authors.affiliation: Radiation Protection Bureau, 775 Brookfield Rd, A.L. 6302D, Ottawa, ON, K1A 1C1, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Bergman
authors.affiliation: Radiation Protection Bureau, 775 Brookfield Rd, A.L. 6302D, Ottawa, ON, K1A 1C1, Canada.
authors.forename: J-F
authors.initials: JF
authors.lastname: Mercier
authors.affiliation: Radiation Protection Bureau, 775 Brookfield Rd, A.L. 6302D, Ottawa, ON, K1A 1C1, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Genovesi
authors.affiliation: Radiation Protection Bureau, 775 Brookfield Rd, A.L. 6302D, Ottawa, ON, K1A 1C1, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Cooke
authors.affiliation: Radiation Protection Bureau, 775 Brookfield Rd, A.L. 6302D, Ottawa, ON, K1A 1C1, Canada.
authors.forename: B
authors.initials: B
authors.lastname: Todd
authors.affiliation: Radiation Protection Bureau, 775 Brookfield Rd, A.L. 6302D, Ottawa, ON, K1A 1C1, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Sandles
authors.affiliation: Radiation Protection Bureau, 775 Brookfield Rd, A.L. 6302D, Ottawa, ON, K1A 1C1, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Whyte
authors.affiliation: Environment Canada, 867 Lakeshore Road, Burlington, ON, L7S 1A1, Canada.
authors.forename: X
authors.initials: X
authors.lastname: Wang
mesh_terms: D000818:Animals; D050643:Beluga Whale; D002586:Cesium / Q000032:analysis*; D002588:Cesium Radioisotopes / Q000032:analysis; D062406:Fukushima Nuclear Accident; D011834:Radiation Monitoring; D012053:Reindeer
chemical_list: D002588:Cesium Radioisotopes; D002586:Cesium
keywords: Beluga; Caribou; Cesium; Fukushima; Lichens