Lung Function Plaques and Asbestos Related Diseases

There has been a great deal of important research conducted examining the link between asbestos exposure in the workplace and disease development.  One important study is called, "Asbestos-related pleural plaques and lung function" by L. Christine Oliver, MD, Ellen A. Eisen, ScD, Reginald Greene, MD, Nancy L. Sprince, MD - American Journal of Industrial Medicine - Volume 14 Issue 6, Pages 649 – 656.  Here is an excerpt: "Abstract - The present study examines the association between asbestos-related pleural plaques and lung function in a group of workers with occupational exposure to asbestos. Exposure, smoking, and respiratory histories, chest radiographs, flow-volume loops, and single breath DLCOs were obtained on 383 railroad workers. A score based on the ILO-1980 classification system was used to quantify the extent of plaquelike thickening. In order to eliminate potential confounders, we excluded from final analysis subjects with diffuse pleural thickening (n = 10) or small irregular opacities classified as profusion 0/1 or greater (n = 6) on chest radiograph. Definite pleural plaques were observed in 22.6%. The single breath DLCO was similar in the groups with and without plaques (p = 0.0550). Decrement in FVC and the occurrence of pulmonary restriction were associated with the presence of definite plaques (p = 0.0306 and 0.0431, respectively) and with quantitative pleural score (p = 0.0135 and 0.0126), controlling for duration of asbestos exposure and smoking. A test for trend revealed an association between level of diagnostic certainty (none, suspect, definite) for pleural plaques and these measures of lung function (p < 0.02). Our findings reveal an association between asbestos-related pleural plaques and decrement in lung function as measured by FVC and criteria for pulmonary restriction."

A second article is called, "Ecological association between asbestos-related diseases and historical asbestos consumption: an international analysis" by R. Lin, K. Takahashi, A. Karjalainen, T. Hoshuyama, D. Wilson, T. Kameda, C. Chan, C. Wen, S. Furuya, and T. Higashi - The Lancet, Volume 369, Issue 9564, Pages 844-849.  Here is an excerpt: "Abstract - Background - The potential for a global epidemic of asbestos-related diseases is a growing concern. Our aim was to assess the ecological association between national death rates from diseases associated with asbestos and historical consumption of asbestos. Methods - We calculated, for all countries with data, yearly age-adjusted mortality rates by sex (deaths per million population per year) for each disease associated with asbestos (pleural, peritoneal, and all mesothelioma, and asbestosis) in 2000–04 and mean per head asbestos consumption (kg per person per year) in 1960–69. We regressed death rates for the specified diseases against historical asbestos consumption, weighted by the size of sex-specific national populations.

Findings - Historical asbestos consumption was a significant predictor of death for all mesothelioma in both sexes (adjusted R2=0•74, p<0•0001, 2•4-fold [95% CI 2•0–2•9] mortality increase was predicted per unit consumption increase for men; 0•58, p<0•0001, and 1•6-fold [1•4–1•9] mortality increase was predicted for women); for pleural mesothelioma in men (0•29, p=0•0015, 1•8-fold [1•3–2•5]); for peritoneal mesothelioma in both sexes (0•54, p<0•0001, 2•2-fold [1•6–2•9] for men, 0•35, p=0•0008, and 1•4-fold for women [1•2–1•6]); and for asbestosis in men (0•79, p<0•0001, 2•7-fold [2•2–3•4]). Linear regression lines consistently had intercepts near zero."  If you found any of these excerpts interesting, please read the studies in their entirety.  We all owe a debt of gratitude to these researchers.