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This device, on the roof of an office building in San Francisco, is part of a nationwide network of monitoring stations fielded by the U.S. Environmental Protection Agency. The number of nodes in the RadNet network, which collects samples of air, rain, and drinking water and tests them for radioactivity, was recently increased in the wake of the nuclear emergency in Japan.
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Willie Jones is an associate editor at IEEE Spectrum. In addition to editing and planning daily coverage, he manages several of Spectrum's newsletters and contributes regularly to the monthly Big Picture section that appears in the print edition.