AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
A Low-Cost Real-Time Detector for Airborne Asbestos Fibers
CHRIS STOPFORD, Paul Kaye, Edwin Hirst, Richard Greenaway, Zbignieu Ulanowski, University of Hertfordshire
Abstract Number: 95 Working Group: Health Related Aerosols
Abstract Inadvertent inhalation of asbestos fibers and the subsequent development of incurable cancers is a leading cause of work-related deaths throughout the industrialized world. Indeed, in 2010, the World Health Organization estimated that more than 100,000 people die each year from asbestos-related lung cancer, mesothelioma and asbestosis resulting from occupational exposure.
Currently, there is no real-time in situ method for detecting airborne asbestos. We describe a relatively low-cost sensor technology that seeks to address this deficiency. It is based on two complementary measurements: firstly, the analysis of 2-dimensional light scattering patterns from individual particles carried in a sample airflow to allow discrimination of fiber particles from all other particle types; and secondly, the subsequent measurement of the behaviour of each of these fibers during their transit through a magnetic field (produced by two small rare-earth magnets). While most commonly occurring airborne fibers (gypsum, glass, rock-wool, cotton, etc) are unaffected by the magnetic field, asbestos fibers, as a result of their magnetic anisotropy, exhibit strong rotation to align with (or normal to) the field. This rotation is therefore used to discriminate asbestos fibers from other fiber particles that may be present in the aerosol.
Current prototype instruments are capable of analysing up to 600 particles per second and have demonstrated high detection sensitivities for both crocidolite (blue) and chrysotile (white) asbestos. Details of sensitivity estimates together with results from field trials carried out at various building renovation and demolition locations will be presented . The method has been developed with the aim of providing a compact low-cost real-time warning device that can be worn or carried by trades-people such as plumbers, electricians, builders, etc., and others at similar risk from inadvertent exposure to airborne asbestos.