Special concern has been expressed regarding nanoparticles with a high aspect-ratio (high aspect ratio nanoparticles; HARN) i.e. nanoparticles that are fibrous in shape. This concern is based on the potential for such fibre-shaped nanoparticles to behave like asbestos fibres. Exposure to airborne asbestos fibres is associated with a number of severe lung diseases including fibrosis (asbestosis), lung cancer and mesothelioma.
The Objective is to undertake a scoping study that reviews the existing literature and sets out a research strategy towards determining whether such concerns about HARN are well–founded.
The following should be considered:
1. the similarities and differences between HARN and asbestos with regard to the understood mechanisms of asbestos pathogenicity.
2.HARN of various types including carbon nanotubes, nanowires, and nanorods, where appropriate.
The key particle properties to be considered include those that relate to dosimetry, such as deposition, clearance, biopersistence, length, diameter and surface reactivity. The biological activities to be considered include genotoxicity, altered gene expression and inflammation in relation to fibrosis, cancer and mesothelioma.