A new hypothesis from Dr. Brad Black, the longtime medical director of the Center for Asbestos Related Disease, or CARD Clinic in Libby, could be good news for patients suffering from asbestos disease linked to exposure from the W.R. Grace & Co. vermiculite mine.
Black, who has recently entered collaborative research programs with Mount Sinai Hospital in New York City and the University of Western Australia, has proposed that a certain facet of disease related to Libby’s unique amphibole asbestos could be a mechanism of an autoimmune reaction and thus has a possibility to be treated.
“If it is such a mechanism, there are medicines on the shelf right now that could help,” he said. “We are seeing something very unique here, and we want to expand on what we’ve learned already.”
Mount Sinai studies the effects of working with asbestos on pipe fitters and insulation-related jobs in the Northeast, and the University of Western Australia studies the impact of exposure to “blue asbestos” at the defunct mining town of Wittenoom.
Each of the three sites — Libby, Australia and the Northeastern U.S. — mined or worked with a different kind of asbestos and are seeing different cancer and mortality rates, as well as different epidemiological results.
“We have a great opportunity to do comparison studies here,” Black said.
Libby amphibole, unique among asbestos-impacted areas, slowly scars the pleural lining over the course of years before a rapid progression over three to five years. Black believes this rapid worsening of the disease is an autoimmune reaction, something that could be treated if his hypothesis is correct.
“You don’t see the rapid progression like this elsewhere,” Black pointed out. “If you go compare to other populations, like in Perth, Australia, they’ve never seen anything like this.”
Asbestos fibers can be inhaled deeply into the lungs into the alveoli, the hollow sacs from which oxygen is exchanged with the bloodstream. The fibers then cause scarring of the lung tissue, pleural lining (the fluid-filled membrane around the lungs) or even the diaphragm, and also can cause various cancers.
Libby amphibole, while rarely causing lung cancer or mesothelioma, does cause plenty of scarring on the pleural lining. The scarring, known as “plaquing,” hardens and thickens the lining. For the pipe fitters in New York and miners in Australia, the asbestos localizes on a particular area and makes a thick scar.
“The way it scars for Libby amphibole is very different,” Black said. “The Mount Sinai study found large, thick, localized plaquing. Libby’s covers the whole surface. It’s fibrous scarring on the chest wall which keeps normal chest movement from occurring.”
Another unique facet of Libby amphibole is the percentage of exposed people it affects. Black said the pipe fitters in New York see about a 1 percent incidence rate for working with asbestos. In Libby, a full 25 percent of people exposed to Libby amphibole will see some negative effects in their lifetimes.
For Libby, with a death toll reaching well above 340 (with more who may never have been diagnosed), and more than 3,600 individuals diagnosed with pulmonary asbestos-related disease, the true scale of the health crisis still may not be known for many years.
Every year, about 850 new patients come to the CARD Clinic, and 45 percent of those are diagnosed with asbestos-related disease. Black estimates that since 1950, more than 60,000 people may have lived, worked and played in Libby in the middle of the environmental disaster.
“We’ll never know just how big this is,” Black said. “More than 40 percent of our existing patients are from out of the area.”
When the U.S. Environmental Protection Agency first came to town, tremolite was the buzzword. Tremolite is a white or gray mineral of the amphibole group.
Now, the Libby amphibole is known to be just 3 percent tremolite (a regulated type of asbestos) with far greater proportions of winchite and richterite, which are sodium calcium minerals in the amphibole group.
This deadly cocktail made simply living in Libby a risk to a person’s health, whether a person worked in the vermiculite mine or not. The mine operated for decades, closing in 1990.
Libby amphibole has a latency period of 40 years, meaning someone can be exposed to contaminant but won’t show signs of asbestos disease until up to four decades later.
“It’s something not in the books,” Black said. “The doctors at Mount Sinai are working to develop better techniques to quantify it and better ways to educate physicians on what this disease is.”
What’s next for the CARD Clinic will be following up on the autoimmune link first and foremost, but other projects tracking Libby amphibole are also in the works.
The ore mined near Libby was transported all over the country in uncovered train cars. Black wants to look at some affected ports and stations where the rail cars were unloaded. These include Portland, San Francisco, Minneapolis, Omaha, Phoenix, New Orleans, Tampa, Chicago and New York City.
Because of Libby’s unique scarring, X-rays of people who may well have died or been sickened by Libby amphibole would not have shown much or anything amiss. People in all of these towns could have been affected, and the EPA is working with the 28 most contaminated sites.
“We’re going to look at those reports from other cities, W.R. Grace expansion sites,” Black said. “We have reports of a worker’s wife in Toronto who got the disease. We’ve heard of one in California from a man who worked at the train yards.”
While the federal agencies track the complex shipping network where Libby vermiculite was sent, the CARD Clinic hopes to get grant funding to study the potential ramifications of Black’s autoimmune hypothesis. In a few years, he hopes to be able to treat some of the asbestos-related diseases Libby residents have felt for decades.
Reporter Ryan Murray may be reached at 758-4436 or by email at firstname.lastname@example.org.