Study Finds Similarities in Carbon Nanotube and Asbestos Exposure

In a recently published article, “A 3-Dimensional In Vitro Model of Epithelioid Granulomas Induced by High Aspect Ratio Nanomaterials,” five students representing Brown University conducted testing on the effects of Carbon Nanotubes (CNTs) and their similarity to asbestos, which is a recognized carcinogen. The May 18, 2011 article explains that Carbon Nanotubes, or CNTs, are “a commercial success of nanotechnology.” This scientific development has the potential to be implemented in several different medical applications, including biomedical devices, imaging, drug delivery, and tumor targeting, among others. However, this paper explains that the experiments it details are in response to the “uncertainty and controversy surrounding potential adverse environmental and human health effects of engineered nanomaterials.” The adverse effects referred to in the report appear to mimic those associated with asbestos exposure, meaning that contact with these CNTs could eventually lead to the same illnesses and diseases linked to asbestos, like mesothelioma. According to the authors, the model presented in this paper “offers a time and cost-effective platform to evaluate the potential of engineered high aspect ratio nanomaterials.” The authors note that the “asbestos-like behavior of some engineered nanomaterials is a concern for their potential adverse health effects in the lungs and mesothelium.” The work conducted for this paper is supported by the National Institute of Environmental Health Sciences and the National Institute of Health. Substances observed in the study included a control group, crocidolite asbestos, MWCNT (multiwalled carbon nanotubes) 1, MWCNT2, MWCNT3, and carbon black. Carbon black particles and crocidolite asbestos fibers were used because they are a “well-characterized reference material” that compares with the three MWCNTs. Results noted, “increasing levels of expression of these two mediators,” which indicates “progression toward a profibrotic response.” A profibrotic response is a reaction that promotes fibrosis, or the formation of excess fibrous connective tissues that are in either a reparative or reactive process. The type of asbestos used for this study, crocidolite asbestos, is also known as blue asbestos. It is an amphibole found primarily in Southern Africa and Australia and is listed as one of the most hazardous forms of asbestos. In an attempt to cut down on animal testing, some of the nanomaterials were introduced into cultures simulating a tissue environment, in lieu of actual animal exposure. Results from animal testing were collected from previous inhalation studies on rodents. The substance doses were “identified in 2D and 3D cultures in order to minimize acute toxicity and to reflect realistic occupational exposures in humans.” Most of the study’s results showed similar side effects of asbestos fiber and MWCNT exposure. As a result of these condemning research results, further testing and examination of this material will likely impact its commercial potential, as most industrialized nations ban dangerous materials, like asbestos. Sanchez, Vanesa C., Weston, Paula, Yan, Aihui, Hurt, Robert H., Kane, Agnes B., (May 18, 2011) "A 3-Dimensional In Vitro Model of Epithelioid Granulomas Induced by High Aspect Ratio Nanomaterials." Retrieved on June 2, 2011 from Particle and Fibre Toxicology. Previous: Photodynamic Therapy Combined with Radical Pleurectomy Next: Victims in Asbestos Lawsuit Awarded $7.25 Million