Cancer Center to Screen Those Exposed to Vermiculite

Karmanos Cancer Institute Scanning Exposed Miners for Asbestos Diseases

DETROIT, MI-April 23, 2004-After the Environmental Protection Agency (EPA) identified over 200 processing plants that received asbestos-contaminated vermiculite, the Karmanos Cancer Institute in Michigan began a program to diagnose and treat those exposed to the material. The newly-created National Center for Vermiculite and Asbestos-Related Cancers plans to:

  • identify populations that are at risk for asbestos diseases due to vermiculite exposure;
  • provide rapid medical screening for large numbers of people;
  • detect and treat asbestos-related cancers and asbestosis at the early stages; and
  • increase knowledge about the health effects of exposure to asbestos-contaminated vermiculite.

"The overall extent of asbestos-related cancers and other diseases related to vermiculite exposure is unclear but initial studies suggest it is substantial," said Dr. Harvey Pass, professor of surgery at Karmanos. Dr. John Ruckdeschel, the president of the Institute, agrees that vermiculite exposure will become a recognized health issue.

What is Vermiculite and How is It Processed?

Most of the vermiculite used in the United States comes from an asbestos-contaminated mine in Libby, Montana. For decades, Libby's vermiculite miners, their families, and the surrounding communities were exposed to dangerous levels of asbestos. The problem did not stop at Libby, however, since the contaminated vermiculite was shipped to manufacturing plants throughout the nation. According to one estimate, at least 63,073 vermiculite shipments left Libby from 1948 through 1993 (Environmental Working Group, Places That Handled Asbestos Shipments).

A type of ore resembling mica, vermiculite may be processed to form a lightweight material that is used in insulation, fertilizers, potting mixes, and animal feed. Manufacturing facilities, called "expansion plants," work with raw water-containing vermiculite. When the vermiculite is heated to high temperatures, the water becomes steam and flakes of vermiculite spread out and expand (Vermiculite, U.S. Geological Survey). The resulting "popped" or "exfoliated" material is inert and fire resistant. If the vermiculite contains asbestos, the asbestos fibers are released in high amounts during the popping process.

Sites That Received Asbestos-Contaminated Vermiculite

Based on EPA data, the Agency for Toxic Substances and Disease Registry (ATSDR) is studying 200 expansion plants that received Libby vermiculite. As of April 5, 2004, the ATSDR and state health partners have published seven public health consultations about these sites. All reports conclude that employees at plants that processed asbestos-contaminated vermiculite were exposed to high levels of asbestos. Members of their households may also have been exposed to asbestos as well, because asbestos fibers may have been carried home on the employees' clothing, skin and hair. The ASDR is currently publishing reports as they become available. See National Asbestos Exposure Review, Phase 1 Sites, National Map.

In a 1982 report, the EPA had concluded that inhaling asbestos contained in contaminated vermiculite caused serious health problems, but issued no protective regulations (Office of the Inspector General, EPA's Actions Concerning Asbestos-Contaminated Vermiculite). In other reports from the 1980s, the agency estimated that more than 13 million people lived close enough to contaminated vermiculite plants to be exposed to potentially harmful levels of asbestos.

Zonolite Insulation Problems

Consumers may also have been exposed to asbestos in vermiculite in their own homes. Up to 35 million houses contain Zonolite brand insulation, most of which is made from asbestos-contaminated vermiculite, according to a report in the Seattle Post-Intelligencer (May 10, 2002). The asbestos in this insulation can become airborne through home remodeling or repair. For example, drilling in an attic or ceiling containing asbestos insulation can release fibers. The EPA began removing Zonolite insulation from homes in Libby, Montana, in May 2002, and declared a national alert about the product one year later.

Asbestos Diseases Take Decades to Develop

Asbestos diseases take a long time to develop-more than 15 years for asbestosis and at least 30 years for the cancer mesothelioma. Symptoms of respiratory problems such as cough, fatigue, and shortness of breath may be signs of other diseases as well. For these reasons, it is particularly important that anyone who was exposed to asbestos-contaminated vermiculite get regular checkups and tell their doctor about their exposure.

The National Center at Karmanos states that you are a good candidate for an asbestos disease if you:

  • Worked in a vermiculite processing facility;
  • Lived with someone who worked in a vermiculite processing facility;
  • Lived in a house with vermiculite insulation;
  • Currently work in the building trades; or
  • Work in other industries which use or have used asbestos.

We have found that the list of "other industries" that use asbestos is a long one. It includes the automotive industry, shipbuilding,mining, railroads, and appliance repair. Do-it-yourselfers who did home repairs on asbestos-containing appliances can even be at risk, as are home auto mechanics who tinkered with asbestos-containing brakes.

Workers who toil in the iron mines at Michigan's upper peninsula are also at risk for asbestos-related diseases, according to the National Center at Karmanos These Michigan miners and those employed in the Mesabi Iron Range of Minnesota are exposed to taconite, a hard, low-grade iron ore that is often contaminated with asbestos. Karmanos medical staff members hope to examine the iron miners, treat them for respiratory diseases, and keep research records on their health status.

Medical Research at Karmanos

Karmanos is also involved in new treatments for mesothelioma patients, including the use of Alimta® (pemetrexed), a drug that blocks the enzymes necessary for cancer cells to synthesize thymidine and purine. The Food and Drug Administration (FDA) recently approved a combination of Alimta® plus a standard chemotherapy drug, cisplatin, to treat pleural mesothelioma, the form of the disease that attacks the lining of the lungs and chest cavity. Karmanos is enrolling patients in a clinical trial that treats mesothelioma with Alimta® plus gemcitabine, an antimetabolite that may prevent tumor growth. Another clinical trial will look at a combination of Alimta®, surgery, and radiation to slow the spread of pleural mesothelioma tumors.

Karmanos has established a hotline concerning asbestos, vermiculite, mesothelioma, asbestosis, and other asbestos diseases at 888-527-6266. The Institute is one of several medical centers treating asbestos diseases.