 The consensus at the Los Alamos Laboratory was that it was not true, and that Joliot-Curie's results had been distorted by impurities.At the Los Alamos Laboratory, Emilio Segrè's P-5 (Radioactivity) Group set out to measure it in uranium-234, −235 and −238, plutonium, polonium, protactinium and thorium.They were not too worried about the plutonium itself; their main concern was the issue Chadwick had raised about interaction with light element impurities.