Asbestos Identification and Testing - Geology Essay Example

Asbestos refers to six types of minerals that occur naturally consisting of fine, durable fibers that are resistant to heat, chemicals, and fire. It includes actinolite asbestos, crocidolite, anthophyllite asbestos, tremolite asbestos, cummingtonite-grunerite asbestos (amosite), and chrysotile. It is challenging to detect the presence of asbestos in a product or material through visual examination hence laboratory testing is appropriate. Because of this, it is a hard to determine the specific risks asbestos poses to humans. It is, however, a potentially harmful material because exposure to it causes mesothelioma, a cancer that affects the inner part of the lungs and other cancers as well as illnesses related to the lungs.

There are two methods for testing and identifying asbestos: asbestos in air and polarized light microscopy of asbestos. Asbestos in air method is a fully validated approach where airborne asbestos fibers are collected using calibrated sample pumps with mixed-cellulose ester (MCE) filters and analyzed with phase contrast microscopy (PCM). The principle behind this method is that airborne asbestos fibers are captured by drawing air through an MCE filter. The filter has a wedge-shaped portion which is removed and positioned on a microscope slide of a glass and made transparent. PCM is then used to view the measured area. Finally, counting all the fibers that meet the defined criteria for asbestos determines the airborne asbestos concentration.

This method is precisely for fibers, inexpensive, and offers quick analysis. On the other hand, it does not positively identifies asbestos fibers hence requires a great deal of experience. The precision of this method relies on the distribution of fibers on the filter and the sum of the counted threads. Interference can occur during analysis attributed to the presence of fibrous substances. Some of the equipment used during sampling are a filter, cassette, extension cowl, and cellulose. During analysis, following the safety precautions is critical because some of the reagents such as acetone are inflammable hence should not be used near an open flame. Also, any asbestos spills should be cleaned immediately to avoid fiber dispersal. After analysis, the fibers are counted and identified.

The other method used is the polarized light microscopy of asbestos. It is instrumental in the description of asbestos bulk materials analysis and collection by light microscopy approaches which comprise of central-stop dispersion microscopy and phase-polar illumination. The analysis in polarized light microscopy is specific to fibers and offers a quick analysis, requires a short time, and can be performed on the site only if the appropriate equipment is available. However, not all fibers present are seen and requires a well-trained microscopist.

The performance of this method solely depends on the analyst. Therefore, an analyst requires adequate training in the preparation of the sample, experience in the identification, and location of asbestos in the samples. Long, small, or thin materials viewed under the microscope may interfere with the analysis. The sampling equipment includes a knife, tube, scintillation vial and sealing encapsulant. Asbestos is carcinogenic, and hence during sampling, safety must be enhanced by taking small amounts of asbestos, closing the sample container tightly, and using an encapsulant to seal a spot where a sample was taken. During analysis, samples are usually divided into the sample for microscopy and preparation. Every sample undergoes different steps and tests to determine the percentage and identity, hence the separation.

In conclusion, asbestos is a hazardous material that is resistant to heat, fire, and some chemicals. It can be tested and identified using asbestos in air and polarized light microscopy of asbestos methods. Asbestos goes through many processes that require safety because it is carcinogenic and potentially causes mesothelioma, a cancer that affects the inner parts of the lungs and other cancers.

References

Occupational Safety & Health Administration. (n.d.). Alphabetic Index of Sampling and Analytical Methods-A. Retrieved from https://www.osha.gov/dts/sltc/methods/toc.html