A study of miners from the town of Libby, Montana, has reportedly identified for the first time a new type of asbestos disease[i].
The mineral vermiculite was mined in Libby between 1919 and 1990. Though itself relatively harmless, it was contaminated with tremolite, a member of the amphibole asbestos family. Hundreds of people, including miners and residents, have died or become ill from various diseases associated with the mining, although the mining company claimed that it was ‘unaware of the hazards of mining and milling vermiculite’ when it purchased the business from the original owner.
There has been extensive asbestos litigation arising from so called ‘Libby Asbestos’. Indeed, in 2011, a district judge approved a $43 million settlement with more than 1,300 claimants. This was followed by a $25 million settlement, awarded to 1,000 claimants in 2017.[ii]
The new study focused on former mine workers, and found that 87% of the miners exposed to Libby amphibole had abnormalities in the pleura, the lining of the lung in which mesothelioma can develop as a result of asbestos exposure. Characteristic lamellar pleural thickening was found in 68%. This specific type of pleural thickening was found to have greater effects on lung function than other types of pleural thickening, and looks distinct on CT scans.
The researchers have identified this lamellar pleural thickening as a different disease from other asbestos diseases. According to the lead researcher, Dr. Raja Flores, ‘It’s a process that kills people before cancer does, before lung cancer or mesothelioma’, and ‘… it’s killing more of these people than anything else’. He also says that the disease leads to death more quickly than other asbestos-related diseases, and ‘This is a new disease’. [iii]
The contaminated vermiculite was used throughout America for decades and still exists in commercial and residential buildings.
[i] Miller, A. et al. Libby Amphibole Disease: Pulmonary Function and CT Abnormalities in Vermiculite Miners. Journal of Occupational and Environmental Medicine Publish Ahead of Print, (2018). https://journals.lww.com/joem/Abstract/publishahead/Libby_Amphibole_Disease___Pulmonary_Function_and.98765.aspx (Accessed 2 February 2018)
[iii] Research Pinpoints Libby Amphibole Disease. Asbestos.com 4 January 2018. https://www.asbestos.com/news/2018/01/04/libby-amphibole-asbestos-disease/ (Accessed 2 February 2018)