Two years ago, members of anti-nuclear weapons groups began to ask our views about the alarm raised by the International Action Center in its book, Metal of Dishonor, about the use of depleted uranium (DU) penetrators in anti-armor munitions. We were asked whether the hazard was so great that activists should give priority to banning DU. We read Metal of Dishonor and found that, despite the contributions of physicists and radiation-effects analysts, it contained no quantitative risk estimate. We therefore decided to provide the best one we could, using information available in the literature about the health effects of uranium and ionizing radiation. We concluded that, except for soldiers in vehicles when they are struck, or individuals who crawl around inside such vehicles without adequate respiratory protection for extended periods of time later on, the health effects of DU are likely to be very small. The radiation effects would be well below those of natural background radiation and the chemical effects would be well below the thresholds for known toxic effects. Contaminated armored vehicles and pieces of depleted uranium, however, are potential hazards and should be cleaned up or buried—something which was not done in most cases after Desert Storm and is only being done now in Kosovo.