Libby kids at risk for respiratory illness from asbestos exposure.

Jun 04, 2010

Vinikoor, LC, TC Larson, TF Bateson and L Birnbaum. Exposure to asbestos-containing vermiculite ore and respiratory symptoms among individuals who were children while the mine was active in Libby, Montana. Environmental Health Perspectives http://dx.doi.org/10.1289/ehp.0901680.

Synopsis by Patrick H. Ryan

New research connects asbestos-contaminated vermiculite mined in Libby, Mont., to respiratory health effects among adults, who as children, lived in the community when the mine closed 20 years ago.

The vermiculite mined in the small town of Libby, Mont., is associated with the poor respiratory health that now afflicts some people who resided there when they were children, say researchers in the journal Environmental Health Perspectives. The chronic respiratory effects include coughing, shortness of breath and bloody phlegm.

This is the first study to look at chronic respiratory effects of those exposed as children – under the age of 18 – before the mine closed and after through continued exposures from lingering pollution. Current residents – particularly children – also may continue to be at risk for these kind of long-term health effects, which are related to the asbestos found in the vermiculite.

Asbestos, a known carcinogen, contaminates the vermiculite ore mined near LIbby. The asbestos fibers from this ore have been previously linked to asbestosis – a respiratory disease – and mesothelioma – a rare cancer of the linings of the lungs – in mine workers and town residents.

Located in northwestern Montana, Libby was home to the largest vermiculite ore mine in the United States. It operated from 1924 until 1990. Despite the mine's closure, environmental contamination of the town continues. In 2009, the U.S. EPA declared Libby a public health emergency.

Vermiculite has many commercial applications including insulation, soil additives and fertilizers.

In this new study, researchers from the U.S. Environmental Protection Agency, the Agency for Toxic Substances and Disease Registry, and the National Institute of Environmental Health Sciences examined residents of the town who were exposed to the vermiculite as children and adolescents. They used data from a medical screening program of individuals living or working in Libby to determine respiratory symptoms. The participants – who were between the ages of 10 and 29 – were asked how often they participated in activities related to vermiculite exposure, including playing in vermiculite piles, playing along contaminated roads or playing near vermiculite processing facilities. The authors took into account personal information, smoking and other factors that might influence respiratory health.

Those who reported frequently handling of vermiculite, playing near contaminated roads and playing near processing facilities were two to three times more likely to report having a cough, shortness of breath or coughing up bloody phlegm. Other activites associated with repiratory problems were playing at the ball fields near the expansion plant and heating the vermiculite to make it expand/pop. Lung function, however, was not associated with vermiculite exposure.