Radiation levels in the Russian city of Severodvinsk have been found to be 16 times higher than normal.<br />Russia's state meteorological service said on Monday that it's identified four radioactive substances in the area.<br />Severodvinsk is where a mysterious explosion happened on August 8th.<br />The blast is known to have killed at least 5 nuclear specialists.<br />The substances, including technogenic radionuclides, are fast-decaying radioactive substances that would emit inert radioactive gases if exposed to open air.<br />The Russian government admits radiation levels briefly spiked after the explosion.<br />The Kremlin now insists levels have returned to normal,...but questions over the mysterious explosion remain.<br />
