Jeffrey Mine

The Jeffrey Mine was a vast open-pit chrysotile asbestos mine located in Asbestos (now Val-des-Sources), Quebec, Canada. Operating from 1881 until 2012, it was for decades the largest asbestos mine in the world and a primary global source of chrysotile (white asbestos) fiber used in thousands of consumer and industrial products.

Origin

The deposit was discovered in 1881 by William Henry Jeffrey, a local farmer, in the Eastern Townships of Quebec. The mine grew over the 20th century into an immense open pit roughly two kilometers wide and 350 meters deep, and the surrounding town was literally named "Asbestos" until residents voted to rename it Val-des-Sources in 2020.

According to the 1986 Sourcebook on Asbestos Diseases, a compilation by plaintiffs' attorneys, the Jeffrey mill was the world's largest producer of asbestos fiber in 1979, turning out 650,000 tons a year; about 400,000 tons went to the United States and 66,000 tons to other countries.¹ The book gives the mill's owner as Johns-Manville Sales Corporation of Denver, Colorado.¹

Significance in Asbestos Context

For patients trying to trace where the asbestos in a product came from, the Jeffrey Mine matters because Quebec chrysotile dominated North American supply for most of the 20th century. If you worked with insulation, joint compound, brake linings, cement pipe, floor tile, or textiles made in the U.S. or Canada between roughly 1900 and 1990, there is a strong probability that some of the fiber originated at the Jeffrey Mine or its sister Thetford-area mines. In fiber-burden and provenance analysis, the trace-element and morphological signature of Quebec chrysotile (including its well-documented tremolite contamination) is often used by experts to link a patient's tissue or product samples to a Canadian source. The mine's long history also makes it a focus of corporate-conduct evidence, because its operators (notably Johns-Manville and later Canadian Johns-Manville/JM Asbestos) generated extensive internal records about hazards.

Example Sentence

The plaintiff's mineralogy expert testified that the tremolite fibers found in the decedent's lung tissue were consistent with chrysotile sourced from the Jeffrey Mine, which had supplied the manufacturer during the relevant exposure years.

Related Terms

Chrysotile, Thetford Mines, Tremolite Contamination, Johns-Manville, Provenance Analysis, Quebec Asbestos Mining Association

Notes

• If you or a family member worked with asbestos-containing products in North America before 1990, ask your legal team whether product-sourcing records can tie the manufacturer to Quebec chrysotile supply contracts.
• Preserve any product packaging, purchase orders, shipping labels, or employer purchasing records that identify the asbestos supplier. These can establish a chain back to the Jeffrey Mine.
• Quebec chrysotile is known to contain trace tremolite, which is important because tremolite is a highly potent cause of mesothelioma; ask whether tissue fiber analysis was performed and whether tremolite was identified.
• Internal documents from Johns-Manville and related Canadian operators are available through asbestos document archives (such as the UCSF Industry Documents Library) and may be relevant to notice and knowledge issues in your case.

References

1. Barbara J. Peters and George A. Peters, Sourcebook on Asbestos Diseases: Medical, Legal, and Engineering Aspects, vol. 2 (New York: Garland Law Publishing, 1986), p. 169.