An evaluation of the adhesive tape sampling method for estimating surface asbestos concentrations.
Ryan-G; Buchan-RM; Keefe-TJ; McCammon-CS
Appl Occup Environ Hyg 1997 Apr; 12(4):288-292
This study was designed to compare surface asbestos concentrations measured directly from a contaminated surface via scanning electron microscopy (SEM) with concentrations measured by adhesive tape sampling. The tape samples were analyzed by both. SEM and polarized light microscopy (PLM). Two different length criteria were used for fiber counting: 3 microm and 5 microm. Tape samples analyzed by SEM measured 30.6 and 37.9 percent (3 and 5 microm, respectively) of the surface concentrations. PLM-tape samples measured 6.8 and 18.3 percent, respectively. Based on the 3-microm criterion, the mean fiber concentrations of the three sample types (tape-S., tape-TIM, and drywall-SEM) were all significantly different (p = 0.01). Based on the 5-microm criterion, the mean fiber concentrations of the tape-SEM and tape-PLM were not significantly different from one another (p greater than or equal to 0.10) but were significantly less than that for the drywall-SEM samples (p = 0.05). None of the regression analyses (for either length criterion) produced statistically significant correlations of tape concentrations versus drywall concentrations. Fibers thinner than 0.1 microm were not observed in the SEM, while fibers thinner than 0.75 microm were not observed with PLM. The failure to demonstrate statistically significant correlations was felt to be due to the inability to produce a uniform surface of known concentration. If one could produce a uniform surface concentration, tape sampling might very well demonstrate statistically significant correlations. Overall, tape sampling must be regarded as a qualitative method at this time. If one were successful in validating significant correlations, field use of the method will still pose problems due to the amount of surface (environmental) variability that exists. This, however, becomes a sampling strategy problem as opposed to a limitation of the method itself.
Sampling; Sampling-equipment; Sampling-methods; Asbestos-dust; Asbestos-fibers; Surface-properties; Testing-equipment; Surface-properties
U.S. Department of Labor, Occupational Safety and Health Administration, 1999 Broadway, Suite 1690, Denver, Colorado 80202; Department of Environmental Health - Occupational Safety and Health Section, Colorado State University, Fort Collins, Colorado
Applied Occupational and Environmental Hygiene
Colorado State University, Fort Collins, Colorado 80523