With the nasty tendency of its airborne fibers to cause lung cancer, the installation of asbestos building insulation has been banned in many countries for some time now. A lot of buildings still have the insulation, however, the fibers of which can get stirred up when work such as renovations or demolition are being performed. In order to help protect the people performing such work, scientists at the University of Hertfordshire have developed what they say is the world’s first portable, real-time detector of airborne asbestos.
Currently, in order to test for airborne asbestos, there are two main choices.
Most often, a filter is used to collect fibers of various types that are present in the building’s air. Those fibers are subsequently taken to a lab to be counted and X-rayed, to determine if any of them are asbestos. There are also portable real-time fiber detectors that can be used on-site, although they’re unable to differentiate between asbestos and other, less harmful fibrous materials.
The Hertfordshire device starts by shining a laser beam into a stream of air. When that laser light strikes a particle of any type, the object scatters the light in a unique pattern that is sufficient to determine the shape, size, and orientation of the particle – in particular, this scattered light pattern lets the device know if the particle is a fiber of some sort. This process also takes place in existing fiber detectors.
From there, however, the air stream continues through a magnetic field. If any of the identified fibers are asbestos, they will align themselves with the direction of that field – it’s a characteristic that’s unique to asbestos. By once again applying the laser light and analyzing the resulting scatter patterns, the device can tell if the fibers are behaving in this way.
Prototypes are now being tested in a number of locations where asbestos-removal operations are taking place. It is hoped that the first production models may be available for use by tradespeople within 12 to 18 months. Prices are expected to initially be in the US$700 to $800 range, although those numbers may drop as production is increased.
A paper on the research was published today in the journal Optics Express.
Source: The Optical Society
