Despite an ominous increase in radiation from the Chernobyl exclusion zone, experts have concluded that there is no imminent risk of a nuclear disaster. Several monitoring sites reported that the levels of gamma radiation dose rate were exceeded as Russian troops invaded and secured the infamous site. But those levels are likely just due to to the movement of heavy equipment over soil under which radiation-infused dirt is still decaying. In 1986, the meltdown of reactor no. 4 at the Chernobyl site caused what is considered to be the worst nuclear disaster in history. Bruno Merk of the University of Liverpool told New Scientist: “I think as long as there is not a deliberate attack the risk is comparably low.”