Tuesday, 3. May 2011 16:59
Anyone who wants to check all data themselves, do it up. The EPA has a useful tool for looking at their sampling results for radiation, available at EPA Japanese Nuclear Emergency: RadNet Laboratory Data.
Below are summary charts showing Iodine-131 levels in rainwater and in milk, taken as snapshots from that site today. The highest figures are for radioactive iodine found in rainwater samples taken in Boise, Kansas City, Salt Lake, Jacksonville and Richmond, CA. Measured in picocuries, those figures are, respectively, 390, 242, 200, 190, 150 and 138. The sample dates for those are in the March 22 to March 30th range. The highest figures for more recent rainwater samples taken April 4th and 5th containing radioactive iodine are for Oak Ridge, TN, Concord, Denver, Idaho Falls, and Jacksonville. Those figures are, respectively, 54, 47, 43, 32 and 22.
EPA results for milk sampling are highest in Hilo, Hawaii at 18 for Iodine-131, and 19 and 24 for Cesium 137 and Cesium 134. Little Rock, Memphis, Los Angeles and Oakland are next in line, with 8.9, 4, 4 and 3.7, respectively. Oakland also showed 2.5 for Cesium 134. That data was collected April 13th in both Oakland and in Los Angeles. While Iodine 131 accumulates in the thyroid and is dangerous particularly to infants and children, it has a half life of 8 days and is reportedly innocuous after 80 days. Cesium 137 has a half life of 30 years, and, like Cesium 134, accumulates in soft tissue and muscle mimicking potassium and sodium. Cesium 134 has a half life of 2 years. Both are carcinogenic, but reportedly pass through the body more readily than does radioactive iodine.
Now what is a safe level, you may ask? That is where you are going to have to apply your own brainpower. There are EPA safe levels, FDA safe levels, and then the raft of other experts who say that there are no safe levels. For comparison, the EPA safe level for radioactive iodine in drinking water is 3 picocuries per liter, and it presumes that one would be exposed over a lifetime. The FDA safe level for radioactive iodine in water is 4700 picocuries per liter. The EPA has recently shifted to citing the FDA levels, not EPA levels, on their data site. Finally, there are organizations such as the Physicians for Social Responsibility and the National Academy of Sciences quoted below:
“No radiation levels can be shown to be demonstrably safe,” said Dr. Alan H. Lockwood, a professor of neurology and nuclear medicine at the University of Buffalo and a board member of Physicians for Social Responsibility.
Lockwood’s group is joined by the National Academy of Science in saying there is no such thing as a “safe dose” of radiation. The groups issued a statement in the wake of Japan’s Fukushima nuclear plant failure saying decades of research show that any dose of radiation increases an individual’s risk of developing cancer.
Since the March 11 earthquake and tsunami that devastated the Japanese nuclear plant, fallout has led to low but elevated levels of radiation showing up in air, water and milk samples throughout the United States. The main isotope identified has been radioiodine-131, a byproduct of nuclear fission that has been linked to thyroid cancer.
One of the primary problems with the EPA and FDA “safe levels” is that they are, strangely, still extrapolated from the health impact of acute external exposure to radiation at Hiroshima and Nagasaki. Using EPA and FDA guidelines might give you a clear idea of how long it would be safe to sit next to a glass of contaminated milk, but would not be as useful in determining whether you wanted to drink the milk or not. The EPA and FDA levels ignore available epidemiological data of actual health effects from Chernobyl’s fallout, including internal exposure to ingested radioactive iodine in children who drank contaminated milk. Secondly, they are based on statistically acceptable incidents of disease and mortality among the general population, and do not accurately inform an individual’s own calculation of risk/benefit. Again, this quote regarding the US Dept of Energy indicates a problem with assuming safe levels of radiation:
“The U.S. Department of Energy has testified that there is no level of radiation that is so low that it is without health risks,” Jacqueline Cabasso, the Executive Director of the Western States Legal Foundation.
