%0 Journal Article
%T Identification of Asbestos Using Laser-Induced Breakdown Spectroscopy: A Viable Alternative to the Conventional Approach?
%A David M. Benton
%J ISRN Spectroscopy
%D 2013
%R 10.1155/2013/362694
%X Laser-induced breakdown spectroscopy has been performed on isolated samples of six types of asbestos¡ªChrysotile, Crocidolite, Amosite, Anthophyllite, Actinolite, and Tremolite¡ªwith analysis of optical emission in the visible region of the spectrum. The principal elements of Mg, Fe, Si, Na, and Ca have all been identified. By examining peak intensity ratios of these elements it is possible to identify the type of asbestos under examination solely from internal examination of the sample spectra. LIBS offers some significant advantages of speed of analysis and removal of subjectivity with potential for on-site rapid analysis. 1. Introduction Asbestos has been widely used, particularly in the construction industry, because of its strength, flexibility, and resistance to chemical and thermal breakdown. It is now known that inhalation of high levels of asbestos can lead to increased risk of asbestosis, lung cancer, and mesothelioma [1]. Asbestos is considered a hazard to health and its use is positively discouraged. Nevertheless some 15,000 tons were used in the USA in 1999, and it is still in widespread use around the world. Several well-established methods are currently available for identifying asbestos; these are transmission electron microscopy (TEM), scanning electron microscopy (SEM), and polarised light microscopy (PLM). Of these techniques PLM is the most widely used for reasons of cost and speed. The current method of assessing asbestos involves surveying a building for potential materials containing asbestos, taking several small samples and then sending them to a laboratory for analysis. Suspect fibres are manually extracted from the sample and examined using PLM. An assessment of the nature of the fibre is made according to fibre morphology, refractive index, and birefringence. This technique is usually sufficient to determine that the fibre is asbestos and identify its type. However, the process can be time consuming, labour intensive and relies on a potentially subjective assessment of what type of asbestos the fibre is likely to be (influencing the choice of refractive index matching fluid). Certain other fibres such as polyethylene, spider¡¯s web, and several other organic materials can sometimes be mistaken for asbestos using this process unless great care and experience are used in the assessment. If, after completing the above process, the assessment is still not clear SEM can be used and the fibre¡¯s elemental composition can be determined. The ratio of the elements calcium, sodium, iron, and magnesium is a confirmation of the specific type
%U http://www.hindawi.com/journals/isrn.spectroscopy/2013/362694/