Last week, the Quebec Public Health Institute issued a report regarding the potential health hazards carried by the asbestos mineral mines near the town of Thetford Mines. The results of the study showed that residents living near the mines, which are among the town's largest employers, are risking exposure to the dangerous airborne mineral fibers. However, the report did not reach a conclusion on the level of cancer risk that the mines posed to workers and their families.

The provincial health and environmental authorities that called for the report stated that readers should be cautious when interpreting the study's conclusions, as the authors cited levels of "uncertainty" due to restrictions on how the actual asbestos measurements were conducted. The researchers behind the study stated that the methods used to measure the level of asbestos in the air suffered from "methodological limits" and that the "uncertainties" that those limits posed could lead to miscalculations of the risk levels involved in asbestos exposure in the area.

In response to concerns over safety issues at the site, the investigators also reiterated the findings by the United Nations-based World Health Organization, as well as several other independent research efforts, that no "safe level" of asbestos exposure has ever been established. The researchers also cited several studies where patients developed severe lung diseases, such as mesothelioma, even after being exposed to very low levels of asbestos.

One member of the country's Parliament has called on the complete shutdown of all asbestos mines as well as the cessation of the exporting of asbestos-containing material. Mr. Pat Martin, a New Democrat from Manitoba, has stated that he would like to see the asbestos mines "sealed" and has voiced his support on a potential ban on asbestos "in all its forms" within the country's borders, including stopping the practice of exporting asbestos to poorer countries that have neither the technology nor the resources to protect workers from its dangers.

Clément Godbout, president of the country's Chrysotile Institute, an asbestos-industry lobbying group, called the reaction to the study "alarmism" and a politically-motivated attack by those in the government who want to shut down the asbestos mines. Mr. Godbout said that the data supports the idea that, at low levels, exposure to chrysotile asbestos carries "no measurable risk".

As the name of the city implies, Thetford Mines was a town founded on mining and excavation, primarily of asbestos. Miners in south-central Quebec found a large source of asbestos ore in 1876. The fibrous mineral was used extensively in the early and middle decades of the twentieth century as insulation and fireproofing material, which brought jobs, industry and prosperity to the small town. Today, the mines employ nearly four hundred people out of a population of twenty-five thousand.

The study data shows that Thetford Mines residents had seventeen times the incidence rate of mesothelioma than the statistical norm, primarily due to the large concentrations of airborne asbestos. Thetford Mines Mayor Luc Berthold attempted to downplay the results by comparing the death rates from mesothelioma in the town, about one every thirty-five years, to the much higher death rates from other causes over the same time period.

In contrast to the statistics gathered over that time period, many scientists and researchers have established that the incidence of mesothelioma and other asbestos-related lung diseases typically occurs decades after the exposure period. With that in mind, the true conclusions of the Thetford Mines studies may not be known until well into the twenty-first century.

(Mesothelioma News*, 15/12/2009)

* Sources: The Associated Press, Globe and Mail