Despite its established threat to human health, asbestos was once extensively used in construction and manufacturing projects. Although asbestos use is now firmly regulated in the United States, construction projects are often conducted at sites where the mineral naturally occurs or at buildings where asbestos products were used. Sampling tests are commonly used to estimate the amount of asbestos disturbed by the construction as well as the health risk posed to workers.
Samples taken from asbestos worksites are most commonly used to assess the risk for construction workers, individuals who pass through the worksites during construction, workers employed at the finished worksite and residents who live near the area. Calculations project the risk of developing an asbestos-related illness such as malignant mesothelioma, as well as absolute risk, which is the chance of death from a complication of cumulative asbestos exposure.
Risk assessments for asbestos-related diseases are based on the level and extent of a person’s asbestos exposure. Extent includes the number of hours per day, days per year and total years that were spent in an asbestos-contaminated worksite. While extent varies from person to person, the precise level of exposure at a given worksite is determined by analyzing an air or soil sample.
The soil collection method currently used is the Berman and Crump approach. During this process, a soil sample is suspended in a machine called an elutriator. The filters in the machine collect the particles. A microscopic evaluation of the filters projects an estimate of asbestos concentrations in the soil. The modified elutriator method, adopted in 2000, uses the number of overall asbestos structures in the soil to also anticipate the quantity of airborne asbestos.
In September 2008, a new air sampling approach was introduced to more closely reflect the conditions created by the actual construction process. This approach analyzes breathing zone samples taken after soil is mechanically disturbed. Known as activity-based sampling, this method more adequately reflects the risk of asbestos inhalation during common construction activities.
After sampling has been conducted, data quality must be considered and reports must be checked for completion. This process ensures the submission of an accurate report for publication.
Additional information on asbestos and its role in the development of mesothelioma may be found through the Mesothelioma Center.
Source : http://www.asbestos.com/news/2011/04/25/asbestos-sampling-guidelines-for-the-prediction-of-mesothelioma/
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