Background

Asbestos related diseases are the leading cause of occupational death in Europe. Some 500,000 European workers are expected to die by 2030 due to asbestos related diseases. Workers within the construction, demolition and remediation industries are continually exposed to this potent carcinogen through legacy products such as insulation, ceiling panels and water tanks.

Asbestos has been banned for use in many developed countries around the world but it is still mined in countries such as Canada, Russia, China and Kazakhstan (2.2 million tonnes, 2005). Countries which have banned its use for new products have a large stock of existing buildings that contain asbestos and asbestos containing products. Renovation and maintenance activities that disturb this legacy asbestos can generate aerosols of asbestos fibres and expose the worker. There are millions of tonnes of asbestos products in existing buildings across the EU. In the UK any building built before the year 2000 can contain asbestos products.

The International Labour Office estimate that more than 100,000 people die each year due to occupational exposure to asbestos.

Currently, the methods used for detection of asbestos are through air sampling which is sent to a lab for assessment. As this method can take several days to confirm the presence of asbestos, it is often too late to take action. At present, there are no “real time” methods to detect asbestos.

Project Details

In order to address this major European concern, we wish to develop a real time, low cost portable detector that can ALERT our members’ workers that they are being exposed to airborne asbestos fibres. We have identified ground-breaking research carried out by University of Hertfordshire (UH) in the mid-1990s as potentially offering a route to a low cost wearable monitor.

The ALERT project is a real time asbestos detection unit that will provide a warning to workers of the presence or asbestos.

Light scattering techniques used for asbestos detection and developed over a decade ago can now be improved upon and included as part of a low cost detection unit.

Through the development of the ALERT detector, 30 million European workers will have time to protect themselves from the event of asbestos being present.

The original UH patented research developed the technology of spatial light scattering analysis for particle classification and identification however, achieving this in real-time involved detector and processor technologies that a decade ago, were prohibitively expensive and too power-consuming for use in a low-cost portable monitor. Modifying the measurement techniques and quantifying the pattern discrimination algorithms so that they are amenable to development in a low cost, portable unit presents major challenges.

Objectives

• Develop a detector with a spatial arrangement and a pixel resolution providing the ability to discriminate between a non-fibrous particle and a fibrous particle to be better than 95%.
• Develop an air flow nozzle that ensures optimal fibre alignment before the fibres enter the measurement zone to minimise the natural spread of fibre alignments.
• Develop suitable data processing algorithm(s) for ALERT particle classification
• Develop Inlet and Optical system designs to separate and align fibres in a laminar airflow such that residence time in the measurement volume can provide time to make a measurement.
• Demonstrate Breadboard prototype ALERT test-bed system
• Process a minimum of 600 particle classifications per second
• Allow the ability to operate the unit for a minimum of 2 hours without recharging together with easily changeable rechargeable battery
• Validated manufacturing costs of no more than €200-€250 for the tradesperson ALERT units in volumes of >100,000

Progress and Achievements to Date

During the second reporting period, work focused on gaining and improving the scientific knowledge required to enable the development and validation of a proof of concept ALERT Detector. During the second period, work included:

• The design and development of a breadboard offline test bed Alert prototype
• The completion of the magnetic realignment system
• The development of the particle classification algorithm
• Sub-system electronics have been tested in isolation from the rest of the system
• Battery management, laser sub system design have been developed and validated
• The development of performance and user specifications for the ALERT Detector
• CFD modelling to optimise airflow design, construction of a prototype inlet systems and experimentation to ensure model results for the sample inlet design
• The light scattering system used in the ALERT detector has been designed, optically modelled and simulated
• Some laboratory experiments using the prototype ALERT unit have been completed and data collected for use in the development of particle classification algorithms
• Conceptual designs of the unit have been generated