An overview of settled dust analytical methods and their relative effectiveness
Methods for sampling and analyzing asbestos in settled dust can be beneficial to document past (and potentially ongoing) episodes of asbestos contamination and to predict potential problems presented by asbestos-containing dust. Research Triangle Institute conducted an evaluation of several methods for dust collection and analysis, utilizing samples from industrial settings, samples from residential settings, and samples created in a laboratory dust-generation chamber. Sample collection techniques included microvacuuming, wipe sampling, tape sampling, and passive sampling. Analytical methods tested included fiber counting/sizing, fiber mass determination, qualitative analysis, and indirect and direct sample preparation procedures. The test results help illustrate the advantages and disadvantages of each technique. Each of the methods tested has specific attributes and limitations. Because of the inherent complexity of the methods and the typical variability found in real-world samples, numerous samples of each sample type are recommended, including side-by-side duplicates, representative sampling throughout the target area, and repeat sampling to determine temporal effects.