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Indianapolis Air Monitoring Shows No Adverse Impact From Damaged Japanese Nuclear Reactors


By Andy Bowman, Attorney, Bingham Greenebaum Doll LLP

The U.S. EPA maintains a nationwide network of 100 fixed and 40 deployable radiation monitors known as “RadNet” that collect air samples and provide radiation results in near real time. An air particulate radiation monitor is located in Indianapolis. In addition to air monitoring, U.S. EPA monitors radiation levels in precipitation and milk at 30 locations as well as drinking water at 50 locations. Milk is also monitored in Indianapolis on a quarterly basis.

In response to the release of radionuclides from the Fukushima Dai-ichi nuclear reactors damaged during the March 11 earthquake and tsunami in Japan, monitoring results are available to the public on a special U.S. EPA website which can be found at The graphs below are from U.S. EPA’s air particulate radiation monitoring report for Indianapolis as of April 6, 2011. 

The beta gross count rate measures the radiation from all radionuclides that emit beta particles. The beta gross count rate indicates how quickly beta particles are being detected, which indicates how much radioactivity the monitor is measuring. Iodine-131, which is one of the primary radionuclides emitted by the damaged Fukushima Dai-ichi nuclear reactors, emits beta particles.

The gamma data measures radiation from all radionuclides that emit gamma rays and splits them into ranges of energy. Cesium-137, one of the primary radionuclides emitted by the Fukushima Dai-ichi nuclear reactors in Japan, emits gamma rays and beta particles. Gamma radiation from cesium-137 is the primary concern.

According to the U.S. EPA, the levels of both beta particles and gamma rays recorded at the Indianapolis monitor through April 6, 2011, have been thousands of times below any conservative level of concern.


Milk data for Indianapolis have not been published at this time. When the data become available, it will be reported at The U.S. EPA’s website also provides useful information and answers to frequently asked questions about radiation. The following figure from the website places in perspective typical radiation exposures during normal daily life.


Releases of radioactive materials from nuclear facility accidents creates widespread public concern. Even here in Indianapolis, some 6,320 miles from the Fukushima Dai-ichi reactors, there is concern. My wife, who is a pharmacist, tells me that her pharmacy as well as all the company’s other Indianapolis pharmacies have sold out of potassium iodine tablets which may provide some protection of the thyroid gland from exposure to iodine-131 if properly administered. Given the distance the radiation must travel and the relatively short 8-day half-life of iodine-131, it is hoped that these tablets are never needed. I also hope that the hundreds of thousands of unused tablets are properly disposed so that they do not cause environmental damage by being flushed down the drain when their shelf life expires in about 6-7 years. Information about potassium iodine and its use can be found at


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