The use of depleted uranium (DU) in munitions is controversial because of questions about potential long-term health effects. Normal functioning of the kidney, brain, liver, heart, and numerous other systems can be affected by uranium exposure, because uranium is a toxic metal. The aerosol produced during impact and combustion of depleted uranium munitions can potentially contaminate wide areas around the impact sites leading to possible inhalation by human beings. During a three-week period of conflict in 2003 in Iraq, 1,000 to 2,000 tonnes of DU munitions were used.