OTTAWA - NATO officials are concerned "a legacy of doubt" could weaken the alliance if it does not properly address the controversy over whether depleted uranium poses a cancer risk to its troops.

The North Atlantic Treaty Organization fears some of its 19 member countries might opt out of military missions if depleted uranium is, or has been, used in proposed areas of operation.

"This could have profound impacts on future coalition operations and Alliance cohesion," warns a NATO briefing document recently tabled at the alliance's Brussels headquarters.

The document, intended primarily for the eyes of NATO member countries, summarizes the controversy that flared in Europe last month over depleted uranium, and whether it is responsible for a so-called Balkans Syndrome, a label that has been given to unexplained deaths and illness among some alliance troops.

The leukemia deaths of about 20 peacekeepers from Italy, Germany, Portugal, Spain and elsewhere raised concerns about whether the 40,000 anti-tank missiles used during the Kosovo and Bosnia bombing campaigns might be posing a health risk. The weapons were tipped with radioactive depleted uranium.

Since the flare-up of the controversy, NATO health officials have presented a calm and confident public response.

At two Brussels press briefings they restated the fact there is no proven scientific link between exposure to depleted uranium and increased cancer rates, but added that because of the concerns raised, the alliance favours further studies of the issue.

While NATO might have science on its side, the internal document expresses concern that political fallout in some countries over the depleted uranium scare could undermine the strength and solidarity of the alliance.

"Public opinion in many European nations is already skeptical about official advice on health issues following a history of confusion and U-turns on BSE or mad cow disease. No matter what the scientific evidence, it is possible that the current debate over depleted uranium munitions will leave a legacy of doubt and suspicion such that certain NATO allies might be unwilling to become involved in operations -- or the aftermath of operations -- where depleted uranium munitions are used."

The document concludes the level of radiation emitted by depleted uranium is too low to cause cancer and that it is "unlikely to be a source of a 'Balkans Syndrome.' "

It recommends a special NATO committee, recently formed to address the issue, ensure the results of further studies are rapidly disseminated.

"It might well be the case that the committee's mandate should be broadened if studies indicate the presence of a health hazard, but exonerate depleted uranium."

The committee includes representatives from 50 countries and five international organizations.

The report also says NATO should adopt a suggestion by the World Health Organization that calls for cleaning up or cordoning off of heavily bombed areas to minimize radiation exposure.

Since depleted uranium re-emerged as a political issue in Europe last month, the European Parliament passed a resolution calling for a ban on the substance.

The United Nations Environment Program is gathering data on the radiation levels at bomb sites in the Balkans and is to report its findings in a matter of weeks.

Canada has said voluntary testing of its peacekeepers has shown no elevated levels of cancer.

However, Portugal, Norway and Greece are planning to screen soldiers for the effects of depleted uranium, and Russia and Portugal are sending teams of experts to Kosovo.

UN observers have discovered the presence of radioactivity at eight sites in the Yugoslav province where depleted uranium warheads exploded.

And the U. S. warned its NATO allies 18 months ago that U.S. munitions littering Kosovo's countryside after the 1999 NATO air raids posed potential health concerns.

A document titled Hazard Awareness issued by the Joint Chiefs of Staff warned soldiers and civilians against touching spent depleted uranium ammunition or other contaminated materials, according to news reports.

The reports said personnel handling the heads of anti-tank shells or entering wrecked vehicles should wear protective masks and cover exposed skin, and people involved in the more hazardous clearing tasks should undergo health assessments afterward.

Uranium is one of the heaviest metals, which makes it effective in piercing targets such as tanks or concrete. The depleted form is only mildly radioactive, but its dust is considered dangerous if ingested or inhaled.

John Manley, Canada's Minister of Foreign Affairs, is in Brussels today for informal meetings with his NATO counterparts. The ministers are to discuss a range of topics including the future prospects for peace in the Balkans and the U.S. plan to build a missile defence system.

Fears for the future of the NATO alliance have been caused by George W. Bush's ambitious plans for a National Missile Defence shield as well as the possibility of closer European integration.

The President's NMD shield has been opposed by some European powers as well as Russia and China. The Chrétien government has been tepid toward the idea.

Some Western allies, particularly France, say the project would violate the 1972 Anti-Ballistic Missile treaty, seen by Russia as the bedrock of arms control, and could tip the security balance on the continent.

Plans for a 60,000-strong European rapid reaction force have been controversial because of concerns it could replace the need for NATO as a global police organization.

William Cohen, former U.S. defense secretary, has warned an independent EU military contingent could destroy NATO.

British General Sir Peter de la Billiere, a former commander in the Gulf War, predicted transAtlantic ties would weaken.