Libby, Montana: population: approximately 3,000 – a sportsman’s paradise known for its breathtaking scenery and pristine mountains – is home to one of the worst cases of asbestos exposure in U.S. history.
Vermiculite was discovered in Libby in the 1880s by gold miners and was subsequently mined from 1920 – 1990. Vermiculite, a naturally occurring mineral that may contain asbestos, is used in numerous ways including building insulation and as a soil additive. Unfortunately, the vermiculite from the Libby mine was contaminated with a highly toxic form of naturally-occurring asbestos called tremolite-actinolite asbestos. It’s believed that the Libby mine, while it was open, produced close to 80% of the planet’s supply of vermiculite. Of the various types of asbestos, tremolite is considered by many experts to be one of the most carcinogenic.
W.R. Grace owned the Libby, Montana mine from 1963 – 1990. In a 1996 deposition, a former W.R. Grace business manager of the mine stated that W.R. Grace knew of the dangers of asbestos exposure as early as 1956 yet failed to inform its employees, exposing them to life-threatening levels of toxic asbestos. A report by the Montana State Division of Disease Control of the Montana State Board of Health stated that the mine produced “asbestos that was of considerable toxicity to the workers.” According to the report, W. R. Grace knew of the toxic levels of asbestos in the mine when it took over ownership in 1963 but it never informed the workers or the residents of Libby. In 1990, W.R. Grace & Co. ceased mining operations in Libby.
The vermiculate was processed in the dry mill, the primary ore-processing facility. Tests conducted in 1969 revealed that dust from the mill’s largest stack contained twenty percent asbestos and sometimes as high as forty percent. The mill’s largest stack coughed up more than 20,000 pounds of dust a day. Based on those numbers, the dry mill stack emitted at least 5,000 pounds of asbestos a day.
The dust was so thick at times that not only were the mill’s buildings blanketed, but also the laundered clothes drying on clothes lines in nearby yards.
The vermiculite mine was named as the source for asbestos contamination and the ultimate deaths of nearly 200 people. Additional cases of asbestos-related diseases, both occupational and non-occupational were also reported.
In the late 1990s, the citizens of Libby contacted the Environmental Protection Agency (EPA), and voiced their concerns about the potential health hazards of asbestos-contaminated vermiculite mined in their own backyards. The EPA arrived on the scene and began collecting samples of air, soil, dust and insulation used in homes and businesses.
The EPA estimates cleanup of some sort will have to be done on approximately 1,400 private residences. Nearly all of the homes in Libby are insulated with asbestos-contaminated insulation.