One benefit of using thoriated tungsten electrodes is that they require a much lower temperature for welding than pure tungsten. This means that exposure occurs at a relatively slow rate. Still, exposure must be limited.
It is possible to minimize hazards by using thorium-free tungsten electrodes when possible. The American Welding Society (2003) lists cerium, lanthanum, yttrium, and zirconium as possible alternatives to the radioactive thorium. A second line of defense listed by the American Welding Society (2003) is the installation of an effective dust collection system as well as an effective ventilation system. Of course, training and intelligent storage of thorium are also crucial workplace safety measures. Dust generated by grinding should also be collected and properly disposed of, in accordance with local, state and federal regulations (American Welding Society 2003). When adequate precautions and controls are taken, the ill effects of thoriated tungsten electrodes are likely to be minimal.
I would mandate strict controls when thoriated tungsten electrodes or other radioactive elements are used, not only because of the immediate workplace safety hazards but also because of second-hand effects. Dust must be minimized, controlled, collected, and disposed of properly. Hazardous waste disposal specialists will ideally be called in to provide a comprehensive assessment and consultation and possibly provide waste removal.
In addition to the dust and waste removal, I would see to it that employees are well-protected when working with thoriated tungsten electrodes. A thorough training seminar is critical for all employees and not just those working with the welding material. Training will also include contingency plans for accidental exposure. Protective gear will be worn, and should exceed the standards established by federal occupational safety organizations like OSHA. This would also require initial investment that would pay off with the long-term health and safety of employees. I would keep on staff a specialist who would monitor both air quality and the physiological measures of employees so that any accidental or incremental exposure would be recognized immediately. Protective gear will be updated regularly. Efforts at minimizing exposure to hazardous materials and maximizing workplace health and safety is a team effort. Ultimately I will require the assistance of all employees and regulatory staff.
American Welding Society (2003). Safety and Health Fact Sheets. Chapters 4, 11, 27. Retrieved online: http://www.aws.org/technical/facts/index.html
Canadian Centre for Occupational Health and Safety (2010). Fumes and gases. Retrieved.