By Theodora Filis
The background level of radiation in oceans and seas varies around the globe. The primary source of radiation pollution has been nuclear weapons testing in the Pacific Ocean, but some regions have experienced additional inputs. The Irish Sea in 2008 showed elevated levels compared to large ocean basins as a result of radioactive releases from the Sellafield reprocessing facility at Seacastle, U.K. Levels in the Baltic and Black Seas are elevated due to fallout from the 1986 explosion and fire at the Chernobyl nuclear reactor. --Data courtesy of MARIS/IAEA and CMER
Scientists continue to track the many pathways by which radioisotopes from the damaged nuclear reactors at Fukushima make their way into and out of seawater, marine life, and seafloor sediments.
These depend on the behavior and metabolism of an individual animal, the nature of complex coastal and open-ocean processes, and the physical and chemical properties of individual isotopes. Most marine life that becomes contaminated with Fukushima radiation remains near the reactor, but some species, like Bluefin tuna, are far-ranging and even migrate across the Pacific. When these animals leave the Northeast coast of Japan, some isotopes remain in their body, but others, like cesium, naturally flush out of their system. (Credit: Madigan, Baumann, and Fisher )
There are many other sources of radiation pollution. In New Mexico, for example, there was much concern expressed in 1988 over the WIPP Site (Waste Isolation Pilot Project) used to store low-level nuclear waste. Radioactive waste is especially troublesome because some of it has to be secured for up to 250,000 years. This period of time represents about one-fourth of the entire time that humans have been considered as a separate species.
Yucca Mountain, in Nevada, is an often proposed site for nuclear waste storage. Unlike WIPP, Yucca mountain would store waste from nuclear power plants. At the moment, however, Yucca Mountain is off the table as a place to store nuclear waste.
Radioactive waste includes:
used nuclear cores
waste generated by hospitals, universities, and industrial plants.
From 1946 to 1970 the U.S. dumped 11,000 tons of radioactive waste into the ocean. The Farallon Islands, located just west of San Francisco, have 50,000 barrels of radioactive waste located in that area. Near the Farallon site, radioactive levels are 2000 times greater than would be normally expected.
Even more dramatic are the levels of contamination found off the New Jersey shore.
The New Jersey Salem and Hope Creek Generating Stations and Oyster Creek Generating Station have levels of radiation that are 260,000 times the normal level expected.
Fish caught near the New Jersey sites were found to contain levels of Plutonium 5000 times the expected level.
Government and industry experts have identified a wide array of these nuclear power plants including a leaky generator, unreliable controls on a reactor, and workers who were so discouraged by a lack of maintenance that they stopped calling for repairs.
Watchdog groups, like the Union of Concerned Scientists, have called on the commission to close the plants until everything is fixed, but regulators say such drastic action is not needed now.
It is up to each reader to decide if they will trust what the regulators say, or not.