current Epa readings vs past radiological events
From March 18-24, the EPA took 73 air samples at 17 sites, and detected I-131 in 66 of them. A comparison with historical EPA data showed:
The current U.S. median of 0.198 picocuries of I-131 per cubic meter of air was at least 20 times above “normal” levels (0.010) recorded by EPA in early June 1986 when Chernobyl fallout had largely disappeared from the U.S. environment.
Current levels were 46% of peak Chernobyl fallout (0.430, May 11-13, 1986).
Boise ID had a reading 84 times above the normal level in the U.S. on March 23 (0.840, vs. 0.010).
From March 15-21, the EPA took 13 precipitation samples, but did not detect I-131 in any. But from March 22-25, each of 12 samples at 10 sites had detectable levels:
The current U.S. median of 39.6 picocuries of I-131 per liter of precipitation was 20 times above normal levels (2.0) recorded in early May 1986, before Chernobyl fallout arrived.
Current levels were 40% of peak Chernobyl fallout (99.5, May 14-16, 1986).
Boise ID had a reading 121 times above the normal level in the U.S. on March 22 (242, vs.2.0)
Riverside CA, near San Francisco, had a reading 69 times above the normal level in the U.S. (138 on March 22)
Current levels were 52% of the levels in October 1976, after fallout from a large-scale Chinese above-ground atom bomb test reached the U.S. (75.5)
I-131 is a fast-decaying radioactive chemical (half life of 8 days) found only in nuclear weapons explosions and reactor operations. When ingested, it seeks out the thyroid gland, where it kills and injures healthy cells, leading to thyroid cancer and other disorders affecting the organ. I-131 is one of hundreds of radioactive chemicals in reactors, including Strontium-90, Cesium-137, and Plutonium-239. The EPA is tracking several of these chemicals.
To access EPA air and precipitation data, the following web sites can be consulted:
RPHP is a New York-based group of scientists and health professionals who study health hazards of radiation exposure. Its members have published 27 medical journal articles and 7 books on the topic.