Report on Asbestos Exposure from Libby Vermiculite Issued by ATSDRAtlanta, Georgia - A report from the Agency for Toxic Substances and Disease Registry ( ATSDR ) has concluded that employees, their families and those living in close proximity to 28 exfoliation sites may have been exposed to amphibole asbestos from vermiculite that was mined in Libby, Montana between the 1920s and the early 1990s.
Groups of people most at-risk from exposure to this form of asbestos are identified in the report which also provides public health recommendations for the 28 sites and identifies 78 other sites that were also recipients of Libby vermiculite. Located in 36 states, all of the sites except for one are previous vermiculite exfoliation facilities.
There is no research currently linking vermiculite, a group of minerals with a flaky, mica-like structure, often used in insulation and gardening to serious health effects in those exposed to this mineral.
The specific type of vermiculite that was mined in Libby and distributed across the United States, however, was contaminated with amphibole asbestos. This type of asbestos has been linked to a number of pulmonary diseases including mesothelioma, lung cancer and asbestosis. The amount of time between a person's exposure to asbestos and the time one of these diseases develops can be as many as 15 to 30 years.
A process called exfoliation, in which vermiculite is heated until it expands is where workers were exposed to asbestos. The heating process released asbestos fibers into the air where they could be inhaled because the Libby vermiculite contained asbestos.
Anyone who believes that they were exposed to amphibole asbestos are encouraged to discuss the situation with their health care professional. Also, because smoking combined with asbestos exposure greatly increases the risk of developing lung cancer, the ATSDR recommends that smokers who believe they were exposed stop smoking.
William Cibulas, Ph.D., and director of ATSDR's Division of Health Assessment and Consultation said "Even though there are relatively low numbers of people who were exposed to this asbestos, ATSDR along with our public health department partners remain concerned about the health effects of the substance on anyone who worked and lived around these facilities when vermiculite was being actively processed from the Libby mine. People will be better able to understand the potential risks for exposure and what to do if they feel they have been exposed as a result of the information we have developed and shared."
There are three groups identified as being at greatest risk for being exposed to amphibole asbestos:
- Those who worked at some time from the 1920s to the early 1990s in exfoliation facilities.
- Those individuals living in the same household with workers exposed to asbestos on the job-they became exposed through their loved ones clothing that came home with asbestos-laden dust on it.
- Community members, especially children, who were frequently in direct contact with vermiculite and waste rock from these sites.
Dr. Cibulas said "The majority of people working and living around these sites today are not being exposed to Libby Mine asbestos. Our goal is to inform the public and make sure that medical screening is sought out by workers and families who might have been exposed but have not yet received medical attention."
Continued health education is called for those who have been exposed to amphibole asbestos in the ATSDR's report. Health education kits have been prepared by the agency has prepared to help community members, public health and health care professionals.
Investigations conducted by the ATSDR identified that residual amphibole asbestos was likely to remain in exterior soil as well as in settled indoor dust at former exfoliation sites. With a lot of these sites still operational as commercial and industrial facilities, ATSDR recommends that a re-evaluation of the sites take place to learn more about any remaining residual asbestos.
It has also been determined by the ATSDR study that non-exfoliation sites do not require follow-up studies at this time even though they handled vermiculite from Libby. The agency, however, does recommend using the criteria of the U.S. Environmental Protection Agency's ( EPA ) Technical Review Workgroup to use ATSDR's improved methodologies in reviewing existing data for all sites that exfoliated Libby vermiculite.
At the request of EPA in response to documented health reports related to asbestos in Libby, ATSDR began its evaluation of Libby-related vermiculite sites. ATSDR and EPA announced an $8 million initiative to advance the scientific understanding of naturally occurring environmental asbestos-like fibers in May 2008.
The resulting document is titled Summary Report: Exposure to Asbestos-28 sites in the United States containing Vermiculite from Libby, Montana.
Technical assistance will continue to be provided to state and local officials in areas where sites exist by ATSDR, a non-regulatory federal public health agency.
