A Department of Veterans' Affairs study concluded that "the doses received by Australian participants were small. ... Only 2% of participants received more than the current Australian annual dose limit for occupationally exposed persons (20 mSv)." However, such findings are contested. Australian servicemen were ordered to: repeatedly fly through the mushroom clouds from atomic explosions, without protection; and to march into ground zero immediately after bomb detonation. Airborne drifts of radioactive material resulted in "radioactive rain" being dropped on Brisbane and Queensland country areas. A 1999 study for the British Nuclear Test Veterans Association found that 30 per cent of involved veterans had died, mostly in their fifties, from cancers.