Emission Of Airborne Fibers From Mechanically Impacted Asbestos-Cement Sheets And Concentration Of Fibrous Aerosol
Source: Journal of Hazardous Materials
Even though the use of asbestos has been banned or seriously curtailed in most developed nations, its immense popularity during the early to mid 20th century means that huge numbers of structures and products containing it are still a fact of life for millions of people all over the world. These people are all potential victims of asbestos-related diseases, such as mesothelioma and lung cancer. It’s often said that as long as the materials in which the asbestos is a part of remain undisturbed, then the exposure risk in relation to these materials remains low. While this is true, the reality of the situation is more complex than this statement allows. Environmental corrosion of these products could possibly release asbestos fibers in the air, as could unexpected and non-controlled structural trauma, such as earthquakes and vandalism. Although there is a clear need for good models describing fiber dissemination after such events, they have not yet been developed.
In light of these pressing needs, Jozef S. Pastuszka, a researcher with the Siliesian University of Technology in Upper Silesia, Poland, embarked on a study which examined this issue and his findings were published in the Journal of Hazardous Materials.
The study looked at the emission rate of asbestos fibers in relation to age, environmental corrosion and the effects of structural impacts on the samples and compared the resulting fiber concentration levels in these results between heavy urban environments with buildings covered in asbestos-containing cement sheets to rural and suburban environments where buildings did not use the same asbestos-containing sheets.
Samples used for the analysis were taken from the concrete sheets used on the exterior facades of buildings, where the sheets ranged in age from 15 to 35 years. The study found that age itself was not a predictor of increased fiber dissemination, but the quality of the surfaces was significant. Those surfaces considered in good or very good shape, such as those without visible cracks or with only slight cracks emitted smaller fiber amounts than those considered in “bad shape,” where cracks were easily seen.
The study also showed that the indoor air quality of the houses covered in asbestos-cement featured much higher concentrations of asbestos than did those houses which did not use such sheets. This was an important finding because it showed that even though the interior spaces of a building may not contain asbestos in a disturbed form, the fibers released when the external facades were disturbed can become concentrated inside, putting people in such areas at a higher risk for developing lung cancer and mesothelioma.
