KABUL — The top Canadian soldier in Afghanistan said farewell Thursday to troops at Camp Julien near Kabul as they near the end of their six-month rotation, and questioned them on whether they'd be willing to return to the war-ravaged country.

"How many of you would come back a year from now?" asked Maj.-Gen. Andrew Leslie during his final question-and-answer session with several hundred soldiers before their journey home.

A simple show of hands revealed as many as half of those sitting and standing in a semicirle in front of Leslie might want to come back to Kabul to continue in their roles in the NATO-led force to protect the Afghan government.

"I'm not saying you will," stressed the deputy commmander of the International Security Assistance Force (ISAF) after looking over the crowd to guage the reaction.

"I'm just looking at you and trying to figure it out."

"Interesting," he added once all willing hands were raised.

Early next week, the nearly 2,000 Canadian soldiers stationed in or around Kabul as part of ISAF since last August will begin returning to Canada, to be replaced over a four-week period by equal numbers mainly from the Royal 22nd Regiment, commonly known as the Vandoos. Canada is scheduled to take over command of ISAF by mid-February.

Leslie repeated Thursday his earlier prediction that Canada would be unable to keep such a large number of soldiers in Afghanistan beyond August 2004, adding however that he had no doubt that some number of Canadian soldiers would continue to work as part of ISAF beyond that date.

Prime Minister Paul Martin isn't expected to make a decision on whether that will happen, and how many troops might be involved, until late next month at the earliest.

Leslie urged his troops, the bulk of whom hail from the Royal Canadian Regiment, to reveal lessons they learned in Afghanistan to their replacements, so they can carry on without getting hurt or killed.

"Please, pass on all the tricks you've learned, the tips of the trade, to those who are coming to replace you," said Leslie.

"It's critical to ensure that, not only does the job get done, but as many as possible come home safe and sound because this is a dangerous place."

He also tried to reassure the troops that their health should not have been adversely affected by pollutants in the air around Kabul, trying to dispell a rumour that one-third of pollutants in the air consist of fecal dust.

"There's been 400 air samplings taken and nothing significant has been found," Leslie stressed.

"The urban myth that the air is composed of 30 per cent fecal matter is bullshit."

That didn't stop one soldier from later asking Leslie whether concerns about the air quality will be written into their official medical records.

"Everyone who is here will get something put in your medical files, absolutely everybody," assured Leslie.

"I'm like you, I'm kind of interested in this issue as well," he added.

"So if it goes on my file, it's going to go on yours."

Earlier Thursday, Leslie presided over what has so far been the largest handover of heavy weapons from Afghan militia forces to the Afghan national army.

Dozens of trucks lined a road near Camp Julien, carrying what Leslie described as "city killers" -- 100 BM-21 and BM-40 multiple rocket launchers, single-fire artillery guns and other large weapons that are being turned over as part of a program to disarm, demobilize and reintegrate Afghan militia soldiers after more than two decades of fighting.

"This is probably the largest single step towards the demilitarization of Kabul since the end of the war in Afghanistan," said Canadian Ambassador Chris Alexander, who watched in awe as one truck after another carried the weapons off to an ISAF-controlled contonement site.

"To see them moving, under government control, out of harm's way, out of the hands of these factions ... is a wonderful sight, said Alexander."

"Canadians, especially the Canadian Forces, have a lot to be proud of in terms of the role they've played in bringing this about."