The 20-year agreement between the USA and Australia that was signed in 2004 allows the USA to test its new weaponry in Australia and to use Australian military bases, airfields and naval ports. The possible use of depleted uranium (DU) in a new generation of weapons is of special concern as the half-life of DU is 4.5 billion years. In addition, it has been linked to increased cancer rates in locations where DU weaponry has been used in the past, most notably in Puerto Rico and at the Clark Air Field in the Philippines.
a couple of links to get you started if you doubt:
