More bad news for taconite workers along Minnesota’s Canadian border: The number of taconite workers who have died of mesothelioma has risen from 63 to 82 since last year. The increase is further evidence that, for reasons which are still unclear, these miners may be at higher risk for mesothelioma than the general population.
The figures are the latest from an ongoing study on the health effects of the mineral taconite, a form of iron-ore which has been mined in the region since the 1950’s. The $4.9 million dollar Taconite Workers Health Study began in 2008 after a number of taconite workers contracted lung cancer and mesothelioma, the asbestos caused cancer.
Three years into the five-year study, the link between taconite mining and mesothelioma appears to be more certain, if not more explainable. According to the Duluth News Tribune, of the 46,000 taconite works born since 1920, 1,681 developed either mesothelioma or another form of lung cancer. Having finished the data collection phase of the study, the University of Minnesota School of Public Health researchers are beginning to try to understand the origin of the apparent mesothelioma risk.
Early reports on mesothelioma incidence in the Iron Range suggested that the taconite workers may have been exposed to asbestos in the insulation around pipes, furnaces and boilers used in their work. Others believed the asbestos may have been intermixed with the taconite, allowing it to be inhaled as dust during the mining process. Although some recent medical studies have linked asbestos’ toxicity in part to its high iron content, it is unclear whether iron-bearing taconite itself could pose a mesothelioma risk.
Myers, John, “More Iron Range mesothelioma deaths found”, October 17, 2011, Duluth News Tribune website.
Nagai, H et al, “Asbestos surface provides a niche for oxidative modification”, September 2, 2011, Cancer Science, Epub ahead of print.
Toyokuni, S et al, “Mechanisms of asbestos-induced carcinogenesis”, May 2011, Japanese Journal of Hygiene, pp. 562-567.