Dozens of workers from the Teck Cominco lead smelter in Trail, B.C., were exposed to thallium, a rare but highly toxic metal, about a month ago. Several of them are already sick.

The workers are awaiting test results taken Sunday for thallium poisoning. Urine tests taken last week by the company showed levels of the toxic metal were too high and the job site was shut down.

Teck Cominco had hired unionized boilermakers and welders to do maintenance work on a furnace at the smelter about a month ago.

Flu-like symptoms

Soon after starting the job, many of them started to feel flu-like symptoms, such as chills, cold sweats and sore muscles. Some vomited constantly. Others had skin rashes.

"One of the American workers was admitted right away to hospital and he had a swelling of his kidney," said Robert Recknagle, a welder. "You could see it through his shirt."

Many of the workers have been brought to Vancouver for full medical examinations. Others, who work for a U.S. contractor, are in hospital in Spokane, Washington.

In all, about 65 employees who worked in the affected area have been asked by their contractors to undergo testing, said Teck Cominco acting general manager Bill Van Beek.

The company hopes to compare its test results with those taken on the weekend, but the extent of the contamination probably won't be known for at least a week.

Thallium banned rat poison

Thallium occurs as a byproduct of the lead smelting process. It was used as a rat poison until 20 years ago, when it was banned.

It can be absorbed through the skin and can cause serious nerve damage, kidney problems and blindness. The workers say they weren't told they were working around thallium.

A spokesman for the company said they did all they could to keep the workers safe.

The Workers' Compensation Board of British Columbia is investigating the problem. But the workers say they complained to the board before the shutdown, and were told the area was safe.

A board spokesperson was unavailable for comment.

Teck Cominco is a Canadian-based integrated natural resource group with mining, smelting and refining operations in the U.S.A., Canada, Peru and Australia.