Radiation’s Risk to Public Health
From the beginning of the Fukushima nuclear disaster in March 2011, the public was told repeatedly by industry spokesmen and government officials that the radiation discovered in the air, drinking water and food was “safe” or that it did not pose a threat to public health. This unfortunately is not true.
It is the consensus of the medical and scientific community, summarized in the National Research Council BEIR VII report, that there is no safe level of radiation. Any exposure, including exposure to naturally occurring background radiation, creates an increased risk of cancer. The BEIR report concluded that every thousand man-rems of radiation exposure will cause one cancer.
While the risk of low-dose exposure may be very low for a given individual, when large numbers of people are exposed, there are health consequences. If one person receives 1 rem of exposure, he or she has a one in one thousand chance of getting cancer. But if a thousand people are exposed, one of them will get cancer. And if a million people are exposed, one thousand of them will get cancer. If the whole US population is exposed to that dose, there will be 300,000 cases of cancer. So while the dose of radiation in a glass of drinking water may be so low that any one person does not need to take specific protective measures, the cumulative impact on the whole community may be very significant.
There are two other aspects of radiation exposure that we need to understand to properly evaluate the risk to public health:
- Not all people exposed to radiation are affected equally. Children are much more vulnerable than adults to the effects of radiation, and fetuses are even more vulnerable.
- Radiation from internal emitters is very different from external beam radiation. If you are standing near a source of radioactivity like a damaged fuel rod, you are exposed to a given rate of radiation for as long as you are near the fuel rod. But if you inhale or ingest a radioactive particle, that particle will continue to irradiate you for as long as it is in your body and the particle remains radioactive.
Unfortunately, nuclear reactors produce in large quantities a number of radioactive elements that are biologically active—that is, they are actively taken up by the body and incorporated into our tissues.
- Iodine-131 concentrates in the thyroid gland and causes thyroid cancer.
- Cesium-137 behaves like potassium, an essential nutrient, and is absorbed and distributed throughout the body. Cesium-137 has a half-life of 30 years, which means that after 30 years a given amount of the material will have lost only half of its radiation. Cesium ingestion causes a large number of different types of cancer.
- Strontium-90 is chemically similar to calcium. It is deposited in bone and, with its 29 year-half life, continues to irradiate bone and bone marrow for decades. It causes bone cancer and leukemia.
- Plutonium-239 is intensely carcinogenic if inhaled and causes lung cancer in microscopic doses. With a half life of 24,200 years, it remains deadly for hundreds of thousands of years.
Long-lived radioactive isotopes remain incredibly lethal for centuries or even hundreds of thousands of years. Once they are released into the biosphere, they work their way through the ecosystems, as do other industrial toxins; they move up the food chains and become progressively more concentrated in foodstuffs and complex forms of life, including human life. Land which is contaminated by these radioactive poisons becomes unhealthy and even uninhabitable. Thus the accidental or intentional release of massive quantities of long-lived ionizing radiation is an extremely serious threat to health.
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