A team from the International Atomic Energy Agency is due to begin inspections at Iraq's largest nuclear site, the Tuwaitha facility near Baghdad.
Uranium could poison the water supply
Their visit is supposed to measure how much uranium has been taken away by looters since the end of the American-led invasion.
But of wider concern is the health of the looters themselves, who may have been seriously exposed to uranium.
A commonly held view is that uranium is dangerous because it is radioactive.
In fact, radioactivity is usually a small part of the issue - much more seriously, uranium is simply toxic.
Like lead, cadmium and other heavy metals, it poisons parts of the human body.
With uranium, the kidney is especially vulnerable.
Radioactivity becomes a major concern only with highly enriched uranium, manufactured for use in nuclear weapons.
As the Tuwaitha site contained only natural and low-enriched uranium, this should not be a major issue.
Reports from Tuwaitha suggest that hundreds of barrels of liquid containing uranium have been taken from the site.
Some may have been emptied before removal.
How serious a problem this turns out to be depends on what people have done with the barrels.
Uranium has to get into the body to do its damage so if people used the barrels to store water which they then drank, they could face poisoning serious enough to be lethal.
In the longer term, a large number of residents may face poisoning through uranium which has been poured away and which could find its way into groundwater.