Nonpulmonary Outcomes of Asbestos Exposure

Abstract

The adverse pulmonary effects of asbestos are well accepted in scientific circles. However, the extrapulmonary consequences of asbestos exposure are not as clearly defined. In this review the potential for asbestos to produce diseases of the peritoneum, immune, gastrointestinal (GIT), and reproductive systems are explored as evidenced in published, peer-reviewed literature. Several hundred epidemiological, in vivo, and in vitro publications analyzing the extrapulmonary effects of asbestos were used as sources to arrive at the conclusions and to establish areas needing further study. In order to be considered, each study had to monitor extrapulmonary outcomes following exposure to asbestos. The literature supports a strong association between asbestos exposure and peritoneal neoplasms. Correlations between asbestos exposure and immune-related disease are less conclusive; nevertheless, it was concluded from the combined autoimmune studies that there is a possibility for a higher-than-expected risk of systemic autoimmune disease among asbestos-exposed populations. In general, the GIT effects of asbestos exposure appear to be minimal, with the most likely outcome being development of stomach cancer. However, IARC recently concluded the evidence to support asbestos-induced stomach cancer to be “limited.” The strongest evidence for reproductive disease due to asbestos is in regard to ovarian cancer. Unfortunately, effects on fertility and the developing fetus are under-studied. The possibility of other asbestos-induced health effects does exist. These include brain-related tumors, blood disorders due to the mutagenic and hemolytic properties of asbestos, and peritoneal fibrosis. It is clear from the literature that the adverse properties of asbestos are not confined to the pulmonary system.

Prismatic to Asbestiform Offretite from Northern Italy: Occurrence, Morphology and Crystal-Chemistry of a New Potentially Hazardous Zeolite

“…Consequently, small-size fibers should not be excluded from those contributing to the induction of human MM, especially in high exposure environments. This is further supported by the fact that ultrafine fibers are particularly suitable for penetration from the proximal area to the peripheral part of the lung and migration from the lung to the pleura and the other sites within the human [6,77,78]. Therefore, it is difficult to exclude fibers of a particular dimension from those producing disease within the lung or extrapulmonary sites.…”

A historical perspective of immunotoxicology

“…Although some investigators have considered these as adjuvant effects, silica can influence circulating immunocompetent cells, particularly T reg and T resp cells. Correlations between asbestos exposure and autoimmune disease also suggest a higher-than-expected risk of systemic autoimmune disease among asbestos-exposed populations (Bunderson-Schelvan et al, 2011), although in general this association is less compelling than that found with silica. An animal model has been developed for asbestos-induced autoimmune disease, which is significant since the method employs normal rather than genetically prone mice (Pfau et al, 2008).…”

Occupational exposure to asbestos is associated with increased mortality in men recruited for a population-based study in Germany

“…Inhaled asbestos fibers are partly transported out of the lungs by mucociliary clearance and subsequently swallowed [2]. In addition, an inadvertent, direct ingestion of asbestos fibers is possible [8]. In vitro and in vivo studies showed that asbestos fibers penetrated and interacted not only with the mucosal cells of the pulmonary system but also with the mucosal cells of the gastrointestinal tract [27].…”

“…In vitro and in vivo studies showed that asbestos fibers penetrated and interacted not only with the mucosal cells of the pulmonary system but also with the mucosal cells of the gastrointestinal tract [27]. However, evidence regarding the carcinogenic potency of asbestos in the gastrointestinal tract as well as evidence regarding increased mortality from gastrointestinal malignancies in asbestos exposed subjects is limited and inconsistent [8]. Associations of occupational exposure to asbestos with increased mortality risk due to esophageal cancer [28], cancer of the small intestine [28] or cancer of the large intestine [29] have only been detected in single cohort studies.…”

“…There are conflicting results on whether asbestos may be responsible for further, extra-pulmonary diseases. Several studies suggest that asbestos exposure increases the risk for mortality from extra-pulmonary neoplasms [8][9][10] whereas others did not find such associations [8]. Furthermore, non-population-based cohort studies showed that the joint effects of smoking and asbestos led to an increased risk for lung cancer mortality in smokers who were occupationally exposed to asbestos [11][12][13][14].…”