Asbestos Content of Lung Tissue, Lymph Nodes, and Pleural Plaques from Former Shipyard Workers

Abstract

Autopsy samples from eight former shipyard workers were collected from lung parenchyma, tracheal lymph nodes, and pleural plaques. The tissue from each respective area was prepared by a modified bleach digestion technique, and the residue was collected on a 0.2-micron pore polycarbonate or 0.22-micron mixed cellulose ester filter. Quantitation of ferruginous bodies and uncoated fibers was done by light and transmission electron microscopy, respectively. Differences in the asbestos burden were noted for each site. Ferruginous bodies were observed in both parenchyma and nodes but not in plaques. Three subjects were found to have more ferruginous bodies per gram dry weight in their lymph nodes than in their lung parenchyma. Likewise, all subjects were found to have more uncoated fibers per gram in the nodes than in the parenchyma. Amphibole and chrysotile fibers were noted in the lung and extrapulmonary sites, with chrysotile being the predominant asbestiform in plaques. The majority of the uncoated fibers in both the nodes and the plaques were less than or equal to 5 microns in length. However, some fibers with dimensions conforming to the "Stanton hypothesis" reached both areas. These residual patterns most likely reflect the impact of clearance on lung burden as opposed to the eventual accumulation and stasis in the extrapulmonary areas.

Altered functions of alveolar macrophages and NK cells involved in asbestos-related diseases

“…However, many studies have shown the existence of asbestos bodies, fibers of asbestos coated with an iron-rich material, in regional lymph nodes [31,32]. It has also been reported that nonoccupationally and occupationally asbestos-exposed individuals have asbestos in their lymph nodes [33][34][35]. Therefore, it is probable that NK cells suffer the harmful effects of asbestos in lymph nodes as well as in the lungs.…”

Persistence of Natural Mineral Fibers in Human Lungs: An Overview

“…The issue of persistence in animal models is discussed at length elsewhere in these proceedings. Table 1 lists published studies that supply information on the relative proportion of chrysotile and amphiboles found in lung samples (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16). The preparative methods, types of electron microscope, and counting rules used in studies differ markedly, and these differences undoubtedly affect the results.…”

Asbestos-Related Research: First Objectivity then Conclusions

“…The total number of fibrils would increase due to fiber splitting [47,49,50], possibly together with the carcinogenic effect, as the split fibrils can move to the pleura [45,47,48]. Asbestos fibers have been identified in the pleura by autopsy, chrysotile being the predominant asbestos form found in pleural plaques [51] and pleural/mesothelial tissues in general [46,52]. In a singular contradicting report amphibole fibers outnumbered chrysotile ones in anthracotic "black spots" in the parietal pleura sampled during thoracoscopy from all 14 studied individuals [53].…”