Although it is known to cause mesothelioma and a host of other diseases, asbestos is still in use in workplaces around the world. According to the Occupational Safety and Health Administration (OSHA), as many as 1.3 million Americans are exposed to significant amounts of asbestos in the workplace.
Historically, those who mine the raw material are at greatest risk for mesothelioma, along with those who work in construction or in manufacturing asbestos-containing products. Inhaled fibers can cause irritation and inflammation that can trigger mesothelioma and other asbestos related diseases even decades after exposure.
Because higher concentrations of airborne asbestos increase the health risk, workplace monitoring of airborne asbestos is required to help protect workers from mesothelioma and other diseases. Phase contrast microscopy (PCM) is one of the most common methods used. With PCM, a sample is collected on a mixed cellulose ester membrane filter which is then cleared with a chemical solution and the collected fibers are counted under 400x magnification. But PCM requires a high degree of sophistication on the part of the microscopist performing the test. It is also not capable of distinguishing between asbestos and non-asbestos fibers, so all the fibers that meet the counting criteria are counted as asbestos.
Now a group of mechanical engineers in South Korea have developed a an automated system using high-throughput microscopy (HTM) that they say can quickly and accurately distinguish asbestos fibers from other particles on a sample slide. To test the effectiveness of the HTM system, the researchers used the method to measure known concentrations of airborne asbestos at 11 different workplaces where asbestos is used. The results showed “a reasonably good agreement in the asbestos concentration” when compared with conventional testing methods. Because of HTM’s accuracy and higher efficiency, the team suggests that it be considered as an alternative to conventional PCM for preventing mesothelioma and other asbestos related diseases through onsite workplace monitoring.
Mesothelioma is a particularly difficult cancer to treat and nearly all cases would have been avoidable if asbestos had been previously removed from products and workplaces. The fact that asbestos is still ubiquitous means that people of all ages are still being potentially exposed to this mesothelioma-causing carcinogen. New automated tests like HTM may help protect workers from being diagnosed with mesothelioma in the future.
Cho, M et al, “Automated Counting of Airborne Asbestos Fibers by a High-Throughput Microscopy (HTM) Method”, November 2011, Sensors.
Polarized Light Microscopy of Asbestos, Occupational Safety and Health Administration website,
Explanation of Phase Contrast Microscopy (PCM), Abacon Environmental Consultants, Inc.