Workers at Teck Comino’s lead smelter in Trail, B.C. were exposed to dangerous levels of thallium poisoning because the testing procedures used were inadequate.
Contract maintenance workers were repairing a boiler in August at the plant. Dust samples indicated that there was only a trace amount of thallium present. However, when 65 workers began to exhibit flu-like symptoms, further testing of scaling on metal tubes the workers were recoating revealed much higher levels.
Excessive exposure to thallium can cause organ damage and even death. However, medical tests on the workers indicate that it is unlikely any will suffer permanent harm.
The company shut down the plant four days after workers began complaining of illness, when thallium poisoning was first suspected. The Workers Compensation Board visited the plant twice in the preceding week but insists that it acted appropriately given the reported initial test results. The board is now conducting an investigation.
In the meantime, the plant has been closed for two weeks. It’s not clear when it will re-open.