There is no safe level of exposure to ionizing radiation, only legally "allowable" doses. Types of ionizing radiation include gamma rays, beta and alpha particles, and X-rays emitted by radioactive elements — like the iodine-131, cesium-137, strontium-90 and even plutonium-239 — that have been spewed into the air and the sea in huge quantities by the triple reactor meltdowns that began in Japan last year, and that are dispersed to the air, water and to dump sites in smaller amounts by the everyday operation of nuclear power and medicine.
Legally permitted releases of radiation — from landfills, power reactors, research reactors, production reactors and accidents — increase the so-called "background" level of radiation to which the public is exposed. This is allowed in spite of the fact that every federal agency that regulates commercial or industrial releases and medical uses of radiation warns that any and all exposure to either external or internal doses, no matter how small, increases one's risk of cancer. The National Council on Radiation Protection says, "every increment of radiation exposure produces an incremental increase in the risk of cancer."
The Department of Health and Human Services warns that "Ionizing radiation is invisible, high-frequency radiation that can damage the DNA or genes inside the body. Some patients who receive radiation to treat cancer or other conditions may be at increased cancer risk."
Yet when a spill, a venting or even a large radiation disaster happens, government and industry spokespeople, as well as major news organizations, are quick to downplay or outright misstate the well-known and easily accessible facts about radiation's human health and environmental consequences. The second or third sentence in most nuclear "accident" reports often includes the phrase "no immediate danger" or "contamination not at harmful levels."
A classic case is a New York Times report on a study of cancers caused by doses of radiation previously thought to be so low they were harmless. "But even the new estimate that radiation is a more potent carcinogen than previously believed should cause no concern for the average person, experts said," the Times reported, "because the public is not exposed to enough radiation to exceed levels considered safe." This is perfectly untrue.
What should have been noted is that the public is not usually exposed to enough radiation to exceed allowable levels. Safe levels don't exist, and official government assessments make this absolutely clear. Add radiation at any levels and the death rate rises commensurately.
The Environmental Protection Agency says, "Based on current scientific evidence, any exposure to radiation can be harmful or can increase the risk of cancer.... Radiation is a carcinogen. It may also cause other adverse health effects, including genetic defects in the children of exposed parents or mental retardation in the children of mothers exposed during pregnancy."
The National Academy of Sciences, in its seventh book-length report The Biological Effects of Ionizing Radiation, concludes likewise. Committee member Herbert Abrams of Harvard said, "There appears to be no threshold below which exposure can be viewed as harmless."
The Department of Energy, which makes H-bombs and tons of radioactive waste, says about low level radiation, "... the major effect is a very slight increase in cancer risk."
The Nuclear Regulatory Commission says, "... any amount of radiation may pose some risk for causing cancer and hereditary effect.... [A]ny increase in dose, no matter how small, results in an incremental increase in risk."
Take a hint. From Fukushima's hot tuna, to the hot water dumped from Xcel's Monticello reactor, radiation's danger is immediate — although the harm may not appear for 10 to 30 years — and there's no harmless exposure. None.