Exposure to carbon may not increase the risk of death among hardmetal workers.
Workers in the hardmetal industry may not be at a higher risk of death due to their career, despite common beliefs about the profession.
Hardmetal is made by heating tungsten and carbon to create tungsten carbide powder, which is mixed with powdered binders. The mixture is then formed into various shapes prior to heating to more than 1000° C. Since some powdered binders, such as cobalt, can irritate lungs and have been shown to cause cancer in animals, workers wear closed hoods with respirators to prevent adverse events.
Previous small studies have suggested that ingredients in hardmetal can increase the risk of lung cancer in humans; however, findings from a study published by the Journal of Occupational and Environmental Medicine suggest that workers in the hardmetal industry may not face an increased risk of lung cancer or 63 other causes of death.
Included in the study were 32,000 workers from 3 companies at 17 different sites in the United States, UK, Austria, Germany, and Sweden, making it the largest study on the population to date.
"Our findings will affect regulatory agencies and how they set exposure standards," said principal investigator Gary M. Marsh, PhD. "It is very good news that the workers in this industry are not at increased risk of death due to the materials used in their occupation, both for the employees and for the hardmetal industry."
On average, the authors did not find an increased risk of death for hardmetal employees, even those who had worked in the industry for decades and those who worked in the industry before modern respirators, according to the authors.
During the study period, a total of 177 deaths were observed, with 49 related to cancer, 10 from lung cancer, and 3 from chronic obstructive pulmonary disease.
Notably, the authors found that workers who were employed for less than 1 year had a small increase in lung cancer mortality compared with long-term employees. The authors hypothesize that the small increase is unrelated to the hardmetal industry.
"These findings in short-term workers are unlikely due to occupational factors in the hardmetal industry," Dr Marsh said. "Instead they are more likely due to differences in lifestyle and behavior that could impact lung cancer risk, such as higher smoking rates."
The investigators discovered that exposure to tungsten, cobalt, and nickel were all below the threshold value for airborne concentration of chemical substances, set by the American Conference of Governmental Industrial Hygienists and recommended by the Occupational Safety and Health Administration, according to the study.
While the study population tended to be younger, the authors did not note an increased cancer risk for hardmetal workers, the authors concluded.