“High-risk radioactive sources that are not under secure and regulated control, including so-called ‘orphan’ sources, raise serious security and safety concerns,” the International Conference on Security of Radioactive Sources said at the conclusion of a three-day meeting in Vienna. “Effective national infrastructures for the safe and secure management of vulnerable and dangerous radioactive sources are essential for ensuring the long-term security and control of such sources.”Orphaned sources are those that, due to loss, theft, or abandonment, have fallen outside official regulatory control. In some countries, regulatory control of radioactive sources, used extensively in medicine and industry, remains weak, IAEA said. Global fears that terrorists could use radioactive sources to make radiological dispersal devices, or so-called dirty bombs, escalated after the September 2001 terrorist attacks in the United States.To effectively deal with the threat the conference called for new international initiatives aimed at facilitating the location, recovery and securing of high-risk radioactive sources throughout the world, under IAEA aegis. Key recommendations included stronger measures to detect, interdict and respond to illicit trafficking in such sources and concerted efforts by all states and the IAEA to enhance current national and international arrangements to respond proactively to the possible malevolent use of such materials.More than 700 delegates from over 120 countries and global law enforcement agencies attended the conference, which was co-sponsored by the Russian Federation and the United States in co-operation with the European Commission (EC), the European Police Office (EUROPOL), the International Criminal Police Organization (ICPO-Interpol) and the World Customs Organization (WCO).