Former workers at the now defunct Cassiar asbestos mine just south of the Yukon/B.C. border are being urged to watch for signs of cancer.

The mine operated for about 40 years and an estimated 50,000 people worked there, including many Yukoners. It closed in the 1990s.

Mineworkers at Cassiar handled raw asbestos without any protective gear. Asbestos fibres can lodge in the lungs and cause respiratory ailments and cancer decades later.

Lee Loftus with the asbestos workers union in B.C. said former Cassiar workers are in a high risk group.

"You could see the asbestos fibres in the trees in the general neighbourhood, so there was no protection," he said. "They weren't provided with any education on the hazards of asbestos exposure, or how to contain asbestos or how to protect themselves against the exposures that they were receiving."

Loftus said traditional X-rays aren't effective in detecting asbestos-related cancer. He said all former Cassiar workers should tell their doctors about their exposure, and get a CT scan immediately if respiratory problems crop up.

Loftus also advises all former workers to start a claim with the B.C. Workers Compensation Board.