Asbestos Fiber Concentrations in the Lungs of Brake Repair Workers: An Updated Analysis Using Several Regression Methods to Handle Nondetectable Measurements.

OBJECTIVES: The aim of the study was to reanalyze an updated database of lung asbestos fiber levels for 21 brake repair workers who died of mesothelioma using robust maximum likelihood-based regression methods to address nondetectable measurements. METHODS: We applied bivariate normal regression to address the doubly left-censored situation where both the lung fiber concentration of noncommercial (TAA) and commercial amphiboles (AC) were subject to detection limits. For the single left-censored situation, we applied censored normal regression to study the relationship between duration of employment (DOE) and TAA. RESULTS: We found a statistically significant positive relationship between TAA and AC (β = 0.49, 95% confidence interval [CI], 0.11 to 0.86) and a not statistically significant relationship between DOE and TAA (β = 0.02, 95% CI, -0.03 to 0.06). CONCLUSIONS: Our results provide additional support for the conclusion that exposure to commercial amphibole asbestos, and not chrysotile, is related to the occurrence of mesothelioma among some brake workers.

Duke Scholars

Author Victor Louis Roggli Pathology