As the director of the doctoral program in environmental engineering at the University of Baghdad, Al-Azzawi had been researching radioactive contamination in Basra for years. She would go on to publish studies showing that cases of leukemia in children in Basra increased by 60 percent between 1990 and 1997, and that the number of children born with severe birth defects increased by a factor of three.

Al-Azzawi’s research points to depleted uranium as the culprit. Depleted uranium is a by-product of the enrichment of natural uranium, a process used to create fuel rods for nuclear power plants. Due to its incredible density, the United States and United Kingdom have used depleted uranium for tank armor and ammunition during military combat since the early 1990s, during the First Gulf War. While not as radioactive as natural uranium, the metal nevertheless poses a threat.

“The kids were playing on the tanks [leftover from the Gulf War], and they were collecting the bullets,” Al-Azzawi said. “For some of the people, those bullets stayed in their houses for years. It was a disaster.”

According to a report by the United Nations Environment Programme (UNEP), the total amount of depleted uranium fired during the 1991 Gulf War was 300 metric tons, roughly 50 metric tons of ammunition from tanks and 250 metric tons from aircraft. The United States is responsible for the bulk of it; the United Kingdom accounted for less than 100 rounds.

The United States has been similarly opaque about where and how much depleted uranium was used during the 2003 Iraq invasion. But according to the UNEP, figures from various speculative studies estimate that the US-led coalition dispersed anywhere from 170 to 1,700 metric tons of the toxic metal. For its part, the United Kingdom Defense Ministry has released some information about where depleted uranium was fired and has suggested that its own forces accounted for less than 2 metric tons.

War and the environment: The disturbing and under-researched legacy of depleted uranium weapons – Bulletin of the Atomic Scientists