New survey reveals the extent of contamination in North America

Feb 23, 2012 09:52 GMT  ·  By
This is the Fukushima Daiichi nuclear power plant, seen before the March 11, 2011 explosions
   This is the Fukushima Daiichi nuclear power plant, seen before the March 11, 2011 explosions

An investigation conducted by experts at that United States Geological Survey (USGS) has revealed that radiations released following the nuclear disaster at the Fukushima Daiichi nuclear power plant can be measured throughout the United States.

The group took air samples from 167 sites all over the country, and discovered traces of radioactive materials at nearly 20 percent of them. Only minimal amounts of radioactive fallout are present in precipitations, so it cannot cause any harm to human health.

The survey was released yesterday, February 22, and is available online here. The investigation was carried out under the National Atmospheric Deposition Program (NADP), and revealed radiation levels consistent with those measured by the US Environmental Protection Agency (EPA).

In fact, the document shows that there is very little difference between levels measured by EPA in the weeks following the March 11, 2011 event and those measured in 2012. Public health concerns are not on the table at this point, authorities agree.

It's also important to know that many of the NADP test sites are located outside major urban areas, so the measurements are more representatives for air quality throughout the US. Pollution covering large cities could have influenced the overall results of the study.

“Japan's unfortunate nuclear nightmare provides a rare opportunity for US scientists to test an infrequently needed national capability for detecting and monitoring nuclear fallout over a wide network,” explains Marcia McNutt, the director of the USGS.

“Had this been a national incident, NADP would have revealed the spatial and temporal patterns of radioactive contamination in order to help protect people and the environment,” she goes on to say.

Among the most well represented radioactive materials in air and precipitation samples, experts identified iodine-131, cesium-134 and cesium-137. The West Coast, central and northern Rocky Mountain States and the eastern US were the most severely affected.

“This analysis provides scientifically valid measurements of radioactive fallout in precipitation over North America, which helps add more details to the picture of fallout in the U.S in the weeks following the Fukushima incident,” USGS chemist and study leader Greg Wetherbee adds.

“NADP and USGS demonstrated that this network enhances national capabilities to monitor radionuclides in precipitation following releases to the atmosphere,” he concludes.