The March 11, 2011 earthquake in Japan and the subsequent tsunami damaged and disrupted cooling systems at the Fukushima Daiichi nuclear power facility. Contamination of land and seas surrounding the site, as well as food supplies and drinking water, is being reported. Small but measurable quantities of radioactivity have been detected in the atmosphere over the US, including aerosol samples collected at the Woods Hole Oceanographic Institution, where I-131 was seen to increase to detectable levels as of March 21-22, and is continuing to increase.
With funding through this Grant for Rapid Response Research (RAPID), investigators at the Woods Hole Oceanographic Institution will establish a baseline radionuclide data set for the Atlantic and Pacific using an east to west network of sampling stations where they have the ability to sample regularly. The sites where the principal investigator has thus far made contact and has arrangements for sampling assistance include: Bermuda, WHOI, Santa Barbara Channel, Hawaii, Midway, Guam, and closer to the site in collaboration with Japanese scientists.
Intellectual Merit: Establishing early activities after an accidental release of man-made radionuclides is key to understanding both the magnitude of the release and public health issues, as well as setting the stage for the use of the longer lived radionuclides as tracers in subsequent studies by the community to understand ocean processes. To put the total potential Fukushima Daiichi source in perspective, all of the atmospheric weapons testing in the 1950?s and 60?s released 36 million Curies of Cs-137, Chernobyl 1-3 million Curies, and Three Mile Island only 10 Curies. At Fukushima, the potential source of Cs-137 in the reactor cores is 67 million Curies and 180 million Curies in the spent fuel ponds.
Broader Impacts: Data collected during this project will be shared with the larger community at both scientific meetings and deposited in appropriate data bases (WHOI BCO-DMO and IAEA Global Marine Radioactivity Database (GLOMARD)). The sampling network can be used to inform policy makers of radioactivity levels to consider for fisheries and human health. Collaboration with the Japanese is important to the success of this effort for both access to data and sampling in coastal waters, and the WHOI team will build upon existing relationships with JAMSTEC established under prior NSF funding (VERTIGO project). They will also include other Japanese universities and national labs that are monitoring radionuclides in air, land and oceans, as well as share data with the broader international community. In addition to building international relationships, the collaboration with H. Dulaiova at U. Hawaii will serve to mentor junior faculty and students at a U.S. university. The PI has already helped develop a web site at WHOI in response to the Japanese crisis and had several interviews with the media (web, print, TV). Public outreach is important as anxieties over radioactivity run high, and these results need to be put in context of natural sources of radiation, the scales and pathways of exposure and relative risks to society.
The triple disaster of the March 11, 2011, earthquake, tsunami, and subsequent radiation releases at Fukushima Dai-ichi were unprecedented events for the oceans, including being the largest accidental release of man-made radionuclides to the oceans in history. This study was designed to establish a baseline for the levels of key radionuclide contaminants in the Atlantic and Pacific oceans, and to collect aerosol samples in Woods Hole Massachusetts. For the ocean baseline, we had several groups collect seawater samples (20 Liters) in March and April for analysis of cesium isotopes. From the ratio of cesium-134 to cesium-137, we can uniquely determine if the contamination came from Fukushima or other sources (such as prior fallout from atmospheric nuclear testing in the 1960’s). Samples were collected (East to West) from Bermuda, Woods Hole, Santa Barbara, Hawaii, Mid-Way and Guam. Analysis thus far show only slight evidence of Fukushima cesium in samples collected off Santa Barbara in March, 2011 (analyses of Hawaii, Guam and Mid-Way are being conducted under separate funding by H. Dulaiova, U. Hawaii). This fits with our understanding of the release of these contaminants, which was low in the "far field" as concentrations in the atmosphere- as measured with the arrival of air born Fukushima cesium 134, cesium 137 and iodine-131 after March 21 in Woods Hole- were too low to cause wide spread ocean increases in Fukushima contaminants. This project also led to development of a new method for measuring cesium isotopes in the ocean, which allowed for a more complete sampling of cesium in the ocean in the "near field" during a research cruise off Japan in June 2011 (the cruise was funded by the Gordon and Betty Moore Foundation). During that cruise, we detected Fukushima radionuclides, in particular cesium isotopes, in waters 20-400 miles off shore. We addressed risks to public health and marine biota by showing that while Cs isotopes were elevated 10-1000 times over prior levels in waters off Japan, radiation risks due to these radionuclides are below those generally considered harmful to marine animals and human consumers, and even below those from naturally occurring radionuclides. Data are available on an open data management web site: http://osprey.bco-dmo.org/project.cfm?flag=viewd&id=186&sortby=project . Results from these studies have also been widely shared with public audiences and the media. A selection of the more than 50 interviews and media reports can be found at: www.whoi.edu/page.do?pid=69136 . Also listed below are several articles written by our group in response to the public interest in marine radioactivity in general, and Fukushima contaminants in particular. Buesseler, K. O. March 2012 What the Fukushima accident did to the ocean. CNN op-ed Fisher, N. S. and Buesseler, K. O. (2011). Tracking Fukushima radionuclides: A research cruise in Japanese waters. Bulletin of the Atomic Scientists, July 19. Japan 2011. WHOI web site with links, articles, video. Buesseler, Ken (April 26, 2011). Japan's irradiated waters: How worried should we be? CNN Opinion on-line.
