Although the five-year study into the increased rate of mesothelioma among workers in the Iron Range area of northern Minnesota is not yet complete, researchers recently gave reporters an update on their progress. Thus far, they said, they have yet to find a solid, conclusive source of the asbestos exposure that has caused more than 80 Iron Range miners to succumb to mesothelioma in the last few years.
According to the study, the rate of fatal mesothelioma among people who live and work in the Iron Range is 300 percent higher than the general population in Minnesota. Previously, it was believed that the increased rate was caused by the taconite mining process, specifically from the minerals that are released when low-grade iron is mined and processed into taconite pellets.
While researchers have not ruled that out, they say that their research thus far has not uncovered a definitive causal link between mesothelioma and the taconite iron ore industry. Further, they says that they have not found many of the traditional asbestos-sized mineral fibers that cause mesothelioma, and are now focused on the shorter fibers known as "elongated mineral particles," which are not technically asbestos.
As a result, researchers are now looking into the study subjects' employment history to determine whether the asbestos exposure may have occurred at previous commonly-held jobs such as building ships or working on Navy vessels. It would be highly coincidental, however, if all of those people with such a similar history had converged on the Iron Range at the same time, resulting in that elevated mesothelioma rate.
You can read more about the Iron Range study in our previous mesothelioma blog post.
Source: Duluth News Tribune, "Iron Range mesothelioma study advancing," John Myers, June 1, 2012