PRISTINA, Yugoslavia, Jan 9 (AFP) - A string of high-level international delegations were due in Kosovo Tuesday to examine scientific studies into the potential health risks posed by the use of depleted uranium shells.

As fears mount that peacekeepers serving with NATO-led peacekeeping forces in Bosnia and Kosovo could have been poisoned by radioactive dust left behind following the Alliance's Balkans air campaigns, national representatives were queuing up to visit the province.

The Portuguese defence and interior ministers, Julio Castro Caldas and Severiano Teixeira, were due to arrive late Tuesday and travel to meet their country's contingent in the KFOR peacekeeping force, force spokesman Captain Richard Kusak said.

Science and Technology Minister Mariano Gago is also due in the UN-run province. He was to meet with representatives of the Portuguese Institute for Technology and Nuclear Power, which is investigating DU contaminated sites.

NATO's scientific committee was meeting Tuesday in Brussels to discuss the issue ahead of a full meeting of the North Atlantic Council Wednesday, following calls for a full inquiry into the alleged dangers posed by DU.

The Alliance's own experts have dismissed the risk as "virtually" zero, but NATO Secretary General George Robertson asked military authorities to draw up a report as soon as possible on potentially affected sites.

Portugal has 347 personnel attached to KFOR, mainly based in the western town of Klina, which is near several sites struck by DU shells fired at Yugoslav forces by US jets during NATO's 1999 air campaign.

The Portuguese press has reported five suspected cases -- two of them fatal -- of cancers among Portuguese Balkans veterans, amid claims DU dust can cause leukemia.

Also due in Kosovo Tuesday were President Leonid Kuchma of Ukraine and and President Aleksander Kwasniewski of Poland, Kusak said.

Poland and Ukraine operate a joint KFOR battallion totalling some 1,700 troops, and both contribute large contingents to Kosovo's international UN police force.

Neither country has reported any suspected cases of so-called "Balkans syndrome" in its personnel, but both leaders are expected to hold talks on the issue with KFOR officers and Kosovo's UN administrator, Bernard Kouchner.

For his part Kouchner was to travel Tuesday to Klina to examine the issue himself before meeting with the foreign delegations, UN officials said.

The doctor and former health minister has asked the World Health Organisation (WHO) to help his own health officials study whether DU has caused any cancers among Kosovo's 1.9 million civilian population.

According to provisional WHO figures released at the weekend there has not been any recorded increase in leukemia since the bombardment, but more complete results are expected later in the week.

Seven Italian soldiers and one aid worker, five Belgian troops, two Dutch nationals, two Spaniards and a Czech have died after tours in the Balkans. Four French soldiers and four Belgians have also contracted leukemia.

Depleted uranium is used in munitions to make bullets or missiles more dense so that they can pierce armor.

The material gives off relatively low levels of radiation, but can be dangerous if ingested, inhaled in dust or if it enters the body through cuts or wounds.

The Portuguese ministers were to spend the night at Klina with the troops before leaving the province Wednesday, Kusak said.