Italian researchers found an elevated incidence of mesothelioma in a study of more than 1,000 miners who worked at an asbestos mine near Turin, Italy. Their findings were reported in the scientific journal Occupational and Environmental Medicine.
The Balangero mine, located near Turin, Italy, used to be Europe’s largest open pit asbestos mine. By the 1970s, the mine produced 130,000 to 160,000 tons per year of chrysotile asbestos. It closed in 1990, two years before Italy banned the mining, marketing and use of all types of asbestos because of the human health hazards.
Medical researchers have been tracking the mine’s former workers to understand better the long-term health effects of breathing asbestos dust. Asbestos-related diseases such as malignant mesothelioma, a cancer of the lining of the lungs or abdomen closely linked to inhaling asbestos fibers, typically don't appear until decades after exposure.
In the 2009 study in the scientific journal Occupational and Environmental Medicine, researchers from four Italian medical institutions reported a significantly higher than expected death rate from pleural and peritoneal mesothelioma among the Balangero miners. All of the cases of mesothelioma occurred more than 30 years after exposure, and two occurred more than 50 years later. Four of the five cases involved miners exposed to asbestos dust for more than 20 years.
The study expands on earlier published research that found an increased risk of oral, laryngeal and pleural cancers among the Balangero asbestos miners, based on health information and mortality data through 1987. The new research tracks 1,056 miners for 16 additional years —through 2003.
The researchers computed expected mortality rates from certain cancers and other causes of death in the province of Turin and throughout Italy. They then compared the expected rates to the actual mortality among the workers employed at the mines starting in 1946 and later. They found four times as many deaths from pleural mesothelioma as expected and increased mortality for pleural and peritoneal cancer combined.
The study also supports a recent conclusion by the U.S. Institute of Medicine that there is sufficient evidence to support an association between asbestos and laryngeal cancer. The study found a greater than 80 percent increased number of deaths from larynegeal cancer above the norm.
Overall, the researchers found excess mortality among the Balangero mine workers from asbestos-related diseases including mesothelioma, lung cancer and asbestosis as well as other alcohol-related conditions such as cirrhosis of the liver.