Post by Ex_Nuke_Troop on Apr 7, 2014 14:35:07 GMT
Modeling the Bioaccumulation Potential of Cesium 137 in a Marine Food Web of the Northwest Pacific, Canada
SETAC North America 32nd Annual Meeting Gobas, F. "Modeling the Bioaccumulation Potential of Cesium 137 in a Ma..." [9080]
ID: 498
SESSION: Environmental Radiation: What Do We Know and What Should We Know for Assessing Risks
[Igor Linkov]
TITLE: Modeling the Bioaccumulation Potential of Cesium 137 in a Marine Food Web of the Northwest
Pacific, Canada
AUTHORS: Juan Alava, Simon Fraser University / Resource & Environmental Management; Frank Gobas,
Simon Fraser University / School of Resource and Environmental Management (Faculty of Environment),
Simon Fraser University
ABSTRACT: The Fukushima nuclear emergency provoked by the tsunami that impacted the north east coast
of Japan on March 11, 2011, emerged as a high priority looming threat due to the risk of radioactive
contamination in the global ocean and biodiversity. On April 11, The Fukushima nuclear plant reached the
severity level 7, the same as the 1986 Chernobyl nuclear disaster. One of the most persistent isotopes produced
and expected to be released by this kind of nuclear accidents was Cesium 137 (137Cs), with a physical half life
of 30 years. In an effort to assess the fate, accumulation and health effects of 137Cs in marine organisms of the
Northwest Pacific after the Fukushima nuclear disaster, we assessed the bioaccumulation potential of 137Cs by
testing steady state and time-dependent bioaccumulation models in an offshore food web that included fisheating,
resident killer whales (Orcinus orca) as one of the major top predators of the marine ecosystems in
British Columbia, Canada. The steady stated model showed that concentrations of 137Cs predicted in the male
killer whale were approximately three orders of magnitude higher relative to its major prey, Chinook salmon,
and > 13,000 times higher compared to phytoplankton. The time-dependent model showed that after 30 days of
radioactive spillage, the 137Cs concentrations accumulate gradually over time in high trophic level organisms
(salmon and killer whales), which exhibited low concentrations likely driven by slow intake rates, while it
bioaccumulates at faster uptake rates in low trophic level, gill ventilating organisms (phytoplankton,
zooplankton, benthic invertebrates and planktivorous fish), exhibiting concentration about one to two orders of
magnitude greater than that in killer whales. At 9125 days (25 years), the predicted concentrations of 137Cs
accumulate in a higher degree in killer whales, being >2 orders of magnitude greater than that predicted in
Chinook salmon and 10,000 times higher relative to phytoplankton. The levels of 137Cs predicted in biota
(shellfish and fish) exceeded well above the 137Cs action level for commercial food/beverage of 1000 Bq/kg
established by the Canadian Guidelines for Consumption following a Nuclear Emergency.
Auto-generated by GAIA Meeting Management System for Juan Jose Alava October 4th 2011 11:38:29 AM
www.researchgate.net/publication/233869698_Modeling_the_Bioaccumulation_Potential_of_Cesium_137_in_a_Marine_Food_Web_of_the_Northwest_Pacific_Canada
SETAC North America 32nd Annual Meeting Gobas, F. "Modeling the Bioaccumulation Potential of Cesium 137 in a Ma..." [9080]
ID: 498
SESSION: Environmental Radiation: What Do We Know and What Should We Know for Assessing Risks
[Igor Linkov]
TITLE: Modeling the Bioaccumulation Potential of Cesium 137 in a Marine Food Web of the Northwest
Pacific, Canada
AUTHORS: Juan Alava, Simon Fraser University / Resource & Environmental Management; Frank Gobas,
Simon Fraser University / School of Resource and Environmental Management (Faculty of Environment),
Simon Fraser University
ABSTRACT: The Fukushima nuclear emergency provoked by the tsunami that impacted the north east coast
of Japan on March 11, 2011, emerged as a high priority looming threat due to the risk of radioactive
contamination in the global ocean and biodiversity. On April 11, The Fukushima nuclear plant reached the
severity level 7, the same as the 1986 Chernobyl nuclear disaster. One of the most persistent isotopes produced
and expected to be released by this kind of nuclear accidents was Cesium 137 (137Cs), with a physical half life
of 30 years. In an effort to assess the fate, accumulation and health effects of 137Cs in marine organisms of the
Northwest Pacific after the Fukushima nuclear disaster, we assessed the bioaccumulation potential of 137Cs by
testing steady state and time-dependent bioaccumulation models in an offshore food web that included fisheating,
resident killer whales (Orcinus orca) as one of the major top predators of the marine ecosystems in
British Columbia, Canada. The steady stated model showed that concentrations of 137Cs predicted in the male
killer whale were approximately three orders of magnitude higher relative to its major prey, Chinook salmon,
and > 13,000 times higher compared to phytoplankton. The time-dependent model showed that after 30 days of
radioactive spillage, the 137Cs concentrations accumulate gradually over time in high trophic level organisms
(salmon and killer whales), which exhibited low concentrations likely driven by slow intake rates, while it
bioaccumulates at faster uptake rates in low trophic level, gill ventilating organisms (phytoplankton,
zooplankton, benthic invertebrates and planktivorous fish), exhibiting concentration about one to two orders of
magnitude greater than that in killer whales. At 9125 days (25 years), the predicted concentrations of 137Cs
accumulate in a higher degree in killer whales, being >2 orders of magnitude greater than that predicted in
Chinook salmon and 10,000 times higher relative to phytoplankton. The levels of 137Cs predicted in biota
(shellfish and fish) exceeded well above the 137Cs action level for commercial food/beverage of 1000 Bq/kg
established by the Canadian Guidelines for Consumption following a Nuclear Emergency.
Auto-generated by GAIA Meeting Management System for Juan Jose Alava October 4th 2011 11:38:29 AM
www.researchgate.net/publication/233869698_Modeling_the_Bioaccumulation_Potential_of_Cesium_137_in_a_Marine_Food_Web_of_the_Northwest_Pacific_Canada