Asbestos, autoimmune diseases linked by study

A study of current and former Libby residents who participated in a screening program for asbestos-related disease is indicating an increased risk of autoimmune disorders among those exposed to asbestos-contaminated vermiculite.

The study, published recently in an environmental health journal, was conducted by Curtis Noonan and Jean Pfau of the Center for Environmental Health Sciences at the University of Montana in Missoula along with Theodore Larson of the federal Agency for Toxic Substances and Disease Registry and Michael Spence of the Montana Department of Health and Human Services. It looked closer at results of the 2000-2001 screening showing 494 of the 7,307 participants reporting that they had one of three autoimmune diseases — lupus, rheumatoid arthritis or scleroderma.

The numbers translate to 6.7 percent of those screened reporting one of the three autoimmune diseases, where less than 1 percent would be expected. The screening included people who had lived, worked, attended school or participated in other activities in the Libby area for at least six months before the end of 1990. The goal of the screening was to identify people with potential asbestos-related disease stemming from exposure to contaminated vermiculite mined and processed near Libby from the 1920s until 1990.

According to the study, there is already considerable evidence supporting a connection between occupational silica exposure and autoimmune disease, but research on a link to asbestos exposure has been much more limited.

The study found that increasing opportunities for vermiculite and/or asbestos exposure resulted in increasing risk for autoimmune diseases. The researchers concluded that their findings support the hypothesis that asbestos exposure is associated with autoimmune disease and that further, more detailed study is warranted.