Asbestos plaques in a typical Veteran's hospital population

Pleural abnormalities and exposure to elongate mineral particles in Minnesota iron ore (taconite) workers

BACKGROUND

Iron ore (taconite) mining and processing are an important industry in northern Minnesota and western Michigan. Concerns around exposures have centered largely on exposure to non-asbestiform amphibole elongate mineral particles (EMPs) found in the eastern portion of the Minnesota iron range.

METHODS

A cross sectional survey was undertaken of current and former taconite workers and spouses along with a detailed exposure assessment. Participants provided an occupational history and had a chest radiograph performed.

RESULTS

A total of 1188 workers participated. Potential exposures to non-amphibole EMPs were evident across multiple jobs in all active mines. Pleural abnormalities were found in 16.8% of workers. There was an association of pleural abnormalities with cumulative EMP exposure that was not specific to the eastern portion of the range.

CONCLUSION

There was evidence of a mild to moderate increase in pleural abnormalities in this population of miners, associated with geographically non-specific cumulative EMP exposure.

Medicolegal Aspects of Asbestos II — Benign Pleural and Lung Diseases

A variety of benign lesions affecting the pleura and/or lung can result from inhaling asbestos fibers. Establishing the presence or absence of these entities often plays an important role in the evaluation, presentation and ultimate resolution of asbestos disease litigation. Forensic pathologists may become involved in these cases to address issues of diagnosis, exposure and/or disease attribution. This article reviews medicolegal issues pertaining to benign asbestos-induced diseases of the pleura and lung.

Radiographic abnormalities and exposure to asbestos-contaminated vermiculite in the community of Libby, Montana, USA

Mining, handling, processing, and personal or commercial use of asbestos-contaminated vermiculite have led to widespread contamination of the Libby, Montana, area. We initiated a medical testing program in response to reports of respiratory illness in the community. The purpose of this analysis was to identify and quantify asbestos-related radiographic abnormalities among persons exposed to vermiculite in Libby and to examine associations between these outcomes and participants' self-reported exposures. A cross-sectional interview and medical testing were conducted in Libby from July through November 2000 and from July through September 2001. A total of 7,307 persons who had lived, worked, or played in Libby for at least 6 months before 31 December 1990 completed the interview. Of those, 6,668 participants > or = 18 years of age received chest radiographs to assess the prevalence of pleural and interstitial abnormalities. We observed pleural abnormalities in 17.8% of participants and interstitial abnormalities in < 1% of participants undergoing chest radiography. We examined 29 occupational, recreational, household, and other exposure pathways in the analysis. The prevalence of pleural abnormalities increased with increasing number of exposure pathways, ranging from 6.7% for those who reported no apparent exposures to 34.6% for those who reported > or = 12 pathways. The factors most strongly associated with pleural abnormalities were being a former W.R. Grace worker, being older, having been a household contact of a W.R. Grace worker, and being a male. In addition to being a former W.R. Grace worker, environmental exposures and other nonoccupational risk factors were also important predictors of asbestos-related radiographic abnormalities.