Marine scientists say they are concerned about radiation spewing from the crippled Japanese nuclear plant.
“Radiation from Japan’s damaged Fukushima Daiichi nuclear plant is accumulating in marine life off Japan’s coast above legal limits for food contamination, Greenpeace said Thursday.
The environmental group said its findings run counter to Japanese government reports and the WoodsHole report that radiation from the Fukushima plant, damaged in the March 11 earthquake and tsunami, is being diluted as time passes.
What is being released from the Fukushima reactors and how dangerous is it?
The Fukushima reactors have been primarily composed of two radioactive substances: iodine-131 and cesium-137. In large doses, both of these isotopes or radionuclides can cause long-term health problems.
Are there different types of radiation?
In general, there are two types of radiation, ionizing and non-ionizing. Non-ionizing radiation includes visible light and radio waves — things that, as the name implies, do not have the ability to form charged ions in other materials. Ionizing radiation, however, can and as a result presents a serious health threat because it can alter the atomic structure of living tissue. Ionizing radiation also comes in several different types, including alpha, beta, and gamma radiation, all with different degrees of concern and health impacts.
How long is the radiation from these substances a risk to humans and the environment?
Radioactive materials are, by their very nature, unstable and decline in strength over time -a long time. This change is measured in half-lives — the length of time it takes for the radiation to decrease by one-half. Every radioactive substance has a different half-life, ranging from fractions of a second to billions of years. Those with longer half-lives are potentially more difficult to deal with because they remain radioactive for longer periods of time. Cesium-137, for example, has a half-life of 30 years and so is a potentially serious health threat for decades or centuries. Iodine-131, on the other hand, has a half-life of just 8 days and so loses much of its potency after just days and effectively disappears after one to two months.
How far can radiation travel?
Ionizing radiation itself cannot travel very far through the air. Typically, dust and other particles, seawater and other liquids, or even gases become radioactive due to exposure to radionuclides and are then transported great distances. In the months and years after the explosion at the Chernobyl nuclear power plant in Ukraine scientists were able to track the spread of radioactive material in the atmosphere and the ocean around the globe. Within a week after the explosions at the Fukushima plant, there were reports of very small increases in the continental U.S.
How will the radioactive material released in Japan affect humans?
People who live near the plants were evacuated to a safe distance restrictions and other precautions recommended by the Japanese government and at-risk individuals needed to take suggested extra precautions such as taking potassium iodide to avoid thyroid problems.
Near the reactors, seafood and other products taken from the sea are not safe for human consumption. However, crops and other vegetation near the reactor site (including grass that cows eat to produce milk) that receive fallout from the atmosphere build up radioactivity can not be eaten even if washed. When these foods are consumed, a person receives much of this dose internally, often a more severe pathway to receive radiation than by external exposure.
Prevailing winds over from Japan blow east towards North America; ocean currents in the region also flow generally east into the North Pacific, though much slower than winds. Radiation from the plants have been found in milk in Phoenix, AZ USA and in the waters over the eastern coast of the US. The concept that this increasing radioactivity is not a point of cern is ridiculous. Drinking milk contaminated with more radiation then is already polluting are environment is not a problem makes no sense. It equates with someone saying well if you take a little more poison daily you won’t notice the difference in your health.
I am disappointed the Woods Hole has played down the dangers of this worldwide radiation increase.
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